diff --git a/inc/Abilities/WorkspaceAbilities.php b/inc/Abilities/WorkspaceAbilities.php
index a8c1b94..9aa350f 100644
--- a/inc/Abilities/WorkspaceAbilities.php
+++ b/inc/Abilities/WorkspaceAbilities.php
@@ -980,22 +980,28 @@ private function registerAbilities(): void {
 								'type'  => 'array',
 								'items' => array(
 									'type'       => 'object',
-									'properties' => array(
-										'handle'      => array( 'type' => 'string' ),
-										'repo'        => array( 'type' => 'string' ),
-										'is_worktree' => array( 'type' => 'boolean' ),
-										'is_primary'  => array( 'type' => 'boolean' ),
-										'external'    => array( 'type' => 'boolean' ),
-										'branch_slug' => array( 'type' => array( 'string', 'null' ) ),
-										'branch'      => array( 'type' => array( 'string', 'null' ) ),
-										'head'        => array( 'type' => 'string' ),
-										'path'        => array( 'type' => 'string' ),
-										'dirty'       => array( 'type' => 'integer' ),
-										'created_at'  => array( 'type' => array( 'string', 'null' ) ),
+										'properties' => array(
+										'handle'          => array( 'type' => 'string' ),
+										'repo'            => array( 'type' => 'string' ),
+										'is_worktree'     => array( 'type' => 'boolean' ),
+										'is_primary'      => array( 'type' => 'boolean' ),
+										'external'        => array( 'type' => 'boolean' ),
+										'branch_slug'     => array( 'type' => array( 'string', 'null' ) ),
+										'branch'          => array( 'type' => array( 'string', 'null' ) ),
+										'head'            => array( 'type' => 'string' ),
+										'path'            => array( 'type' => 'string' ),
+										'dirty'           => array( 'type' => 'integer' ),
+										'created_at'      => array( 'type' => array( 'string', 'null' ) ),
 										'lifecycle_state' => array( 'type' => array( 'string', 'null' ) ),
-										'pr_url'      => array( 'type' => array( 'string', 'null' ) ),
-										'pr_number'   => array( 'type' => array( 'integer', 'null' ) ),
-										'metadata'    => array( 'type' => array( 'object', 'null' ) ),
+										'pr_url'          => array( 'type' => array( 'string', 'null' ) ),
+										'pr_number'       => array( 'type' => array( 'integer', 'null' ) ),
+										'last_touched_at' => array( 'type' => array( 'string', 'null' ) ),
+										'age_days'        => array( 'type' => array( 'integer', 'null' ) ),
+										'size_bytes'      => array( 'type' => array( 'integer', 'null' ) ),
+										'artifact_size_bytes' => array( 'type' => 'integer' ),
+										'artifacts'       => array( 'type' => 'array' ),
+										'stale_reason'    => array( 'type' => array( 'string', 'null' ) ),
+										'metadata'        => array( 'type' => array( 'object', 'null' ) ),
 									),
 								),
 							),
@@ -1100,6 +1106,10 @@ private function registerAbilities(): void {
 								'type'        => 'string',
 								'description' => 'Optional candidate age filter such as 7d, 24h, 30m, or 60s. Uses lifecycle created_at metadata only.',
 							),
+							'sort'        => array(
+								'type'        => 'string',
+								'description' => 'Optional cleanup candidate sort: size or age.',
+							),
 						),
 					),
 					'output_schema'       => array(
@@ -1468,7 +1478,7 @@ public static function worktreePrune( array $input ): array|\WP_Error { // phpcs
 	/**
 	 * Remove merged worktrees across all primary checkouts.
 	 *
-	 * @param array $input Input parameters (dry_run, force, skip_github, apply_plan, older_than).
+	 * @param array $input Input parameters (dry_run, force, skip_github, apply_plan, older_than, sort).
 	 * @return array
 	 */
 	public static function worktreeCleanup( array $input ): array|\WP_Error {
@@ -1484,6 +1494,9 @@ public static function worktreeCleanup( array $input ): array|\WP_Error {
 		if ( isset( $input['older_than'] ) && '' !== trim( (string) $input['older_than'] ) ) {
 			$opts['older_than'] = trim( (string) $input['older_than'] );
 		}
+		if ( isset( $input['sort'] ) && '' !== trim( (string) $input['sort'] ) ) {
+			$opts['sort'] = trim( (string) $input['sort'] );
+		}
 
 		return $workspace->worktree_cleanup_merged( $opts );
 	}
diff --git a/inc/Cli/Commands/WorkspaceCommand.php b/inc/Cli/Commands/WorkspaceCommand.php
index b39e457..154d852 100644
--- a/inc/Cli/Commands/WorkspaceCommand.php
+++ b/inc/Cli/Commands/WorkspaceCommand.php
@@ -1064,21 +1064,32 @@ private function renderGitOperationResult( string $operation, array $result, arr
 	 * [--dry-run]
 	 * : Preview cleanup candidates without removing anything (cleanup only).
 	 *
-	 * [--apply-plan=<file>]
-	 * : Apply a previously reviewed cleanup JSON report. The destructive pass
-	 *   revalidates every planned row and removes only exact current matches.
-	 *
-	 * [--skip-github]
-	 * : Skip the GitHub API lookup and rely only on the local `upstream-gone`
-	 *   signal (cleanup only). Faster, but misses merged branches where the
-	 *   remote branch wasn't auto-deleted.
-	 *
-	 * [--older-than=<duration>]
-	 * : Limit cleanup candidates to worktrees with lifecycle `created_at`
-	 *   metadata older than the compact duration (cleanup only, e.g. 7d, 24h).
-	 *   Candidate worktrees without valid `created_at` metadata are skipped.
-	 *
-	 * [--verbose]
+		 * [--apply-plan=<file>]
+		 * : Apply a previously reviewed cleanup JSON report. The destructive pass
+		 *   revalidates every planned row and removes only exact current matches.
+		 *
+		 * [--skip-github]
+		 * : Skip the GitHub API lookup and rely only on the local `upstream-gone`
+		 *   signal (cleanup only). Faster, but misses merged branches where the
+		 *   remote branch wasn't auto-deleted.
+		 *
+		 * [--older-than=<duration>]
+		 * : Limit cleanup candidates to worktrees with lifecycle `created_at`
+		 *   metadata older than the compact duration (cleanup only, e.g. 7d, 24h).
+		 *   Candidate worktrees without valid `created_at` metadata are skipped.
+		 *
+		 * [--sort=<field>]
+		 * : Sort cleanup candidates by reporting field (cleanup only).
+		 * ---
+		 * options:
+		 *   - size
+		 *   - age
+		 * ---
+		 *
+		 * [--stale]
+		 * : For list, show only worktrees with a stale_reason (old, dirty, or missing metadata).
+		 *
+		 * [--verbose]
 	 * : Show every cleanup row instead of concise samples (cleanup only).
 	 *
 	 * [--only=<section>]
@@ -1277,6 +1288,9 @@ public function worktree( array $args, array $assoc_args ): void {
 				if ( isset( $assoc_args['older-than'] ) && '' !== trim( (string) $assoc_args['older-than'] ) ) {
 					$input['older_than'] = trim( (string) $assoc_args['older-than'] );
 				}
+				if ( isset( $assoc_args['sort'] ) && '' !== trim( (string) $assoc_args['sort'] ) ) {
+					$input['sort'] = trim( (string) $assoc_args['sort'] );
+				}
 				break;
 		}
 
@@ -1307,29 +1321,39 @@ private function renderWorktreeResult( string $operation, array $result, array $
 		switch ( $operation ) {
 			case 'list':
 				$worktrees = $result['worktrees'] ?? array();
+				if ( ! empty( $assoc_args['stale'] ) ) {
+					$worktrees = array_values( array_filter( $worktrees, fn( $wt ) => ! empty( $wt['stale_reason'] ) ) );
+				}
 				if ( empty( $worktrees ) ) {
 					WP_CLI::log( 'No worktrees found.' );
 					return;
 				}
 				$items  = array_map(
 					fn( $wt ) => array(
-						'handle'     => $wt['handle'] ?? '',
-						'repo'       => $wt['repo'] ?? '',
-						'kind'       => ! empty( $wt['is_primary'] ) ? 'primary' : 'worktree',
-						'branch'     => $wt['branch'] ?? '-',
-						'head'       => isset( $wt['head'] ) ? substr( (string) $wt['head'], 0, 7 ) : '-',
-						'dirty'      => (int) ( $wt['dirty'] ?? 0 ),
-						'created_at' => $wt['created_at'] ?? null,
-						'state'      => $wt['lifecycle_state'] ?? null,
-						'pr'         => $wt['pr_url'] ?? null,
-						'metadata'   => $wt['metadata'] ?? null,
-						'path'       => $wt['path'] ?? '',
+						'handle'              => $wt['handle'] ?? '',
+						'repo'                => $wt['repo'] ?? '',
+						'kind'                => ! empty( $wt['is_primary'] ) ? 'primary' : 'worktree',
+						'branch'              => $wt['branch'] ?? '-',
+						'head'                => isset( $wt['head'] ) ? substr( (string) $wt['head'], 0, 7 ) : '-',
+						'dirty'               => (int) ( $wt['dirty'] ?? 0 ),
+						'created_at'          => $wt['created_at'] ?? null,
+						'state'               => $wt['lifecycle_state'] ?? null,
+						'pr'                  => $wt['pr_url'] ?? null,
+						'age_days'            => $wt['age_days'] ?? null,
+						'size_bytes'          => $wt['size_bytes'] ?? null,
+						'size'                => $this->format_bytes( $wt['size_bytes'] ?? null ),
+						'artifact_size_bytes' => $wt['artifact_size_bytes'] ?? 0,
+						'artifacts'           => $this->format_bytes( $wt['artifact_size_bytes'] ?? 0 ),
+						'artifact_paths'      => $wt['artifacts'] ?? array(),
+						'stale'               => $wt['stale_reason'] ?? '',
+						'metadata'            => $wt['metadata'] ?? null,
+						'path'                => $wt['path'] ?? '',
 					),
 					$worktrees
 				);
-				$fields = array( 'handle', 'repo', 'kind', 'branch', 'head', 'dirty', 'state', 'created_at', 'pr', 'path' );
+				$fields = array( 'handle', 'repo', 'kind', 'branch', 'head', 'dirty', 'state', 'created_at', 'pr', 'age_days', 'size', 'artifacts', 'stale', 'path' );
 				if ( in_array( (string) ( $assoc_args['format'] ?? '' ), array( 'json', 'yaml' ), true ) ) {
-					$fields[] = 'metadata';
+					$fields = array( 'handle', 'repo', 'kind', 'branch', 'head', 'dirty', 'state', 'created_at', 'pr', 'age_days', 'size_bytes', 'artifact_size_bytes', 'artifact_paths', 'stale', 'metadata', 'path' );
 				}
 				$this->format_items( $items, $fields, $assoc_args, 'handle' );
 				return;
@@ -1487,8 +1511,29 @@ private function render_worktree_cleanup_result( array $result, array $assoc_arg
 				'count'  => (int) ( $summary['age_filter']['unknown_age'] ?? 0 ),
 			);
 		}
+		$summary_rows[] = array(
+			'metric' => 'total_size',
+			'count'  => $this->format_bytes( $summary['total_size_bytes'] ?? null ),
+		);
+		$summary_rows[] = array(
+			'metric' => 'artifact_size',
+			'count'  => $this->format_bytes( $summary['artifact_size_bytes'] ?? null ),
+		);
 		$this->format_items( $summary_rows, array( 'metric', 'count' ), array( 'format' => 'table' ), 'metric' );
 
+		if ( ! empty( $summary['size_by_repo'] ) && is_array( $summary['size_by_repo'] ) ) {
+			WP_CLI::log( '' );
+			WP_CLI::log( 'Top repos by worktree size:' );
+			$repo_rows = array();
+			foreach ( array_slice( $summary['size_by_repo'], 0, 5, true ) as $repo => $bytes ) {
+				$repo_rows[] = array(
+					'repo' => (string) $repo,
+					'size' => $this->format_bytes( $bytes ),
+				);
+			}
+			$this->format_items( $repo_rows, array( 'repo', 'size' ), array( 'format' => 'table' ), 'size' );
+		}
+
 		if ( '' !== $only ) {
 			WP_CLI::log( sprintf( 'Filter: %s', $only ) );
 		}
@@ -1500,13 +1545,16 @@ private function render_worktree_cleanup_result( array $result, array $assoc_arg
 				fn( $c ) => array(
 					'handle'      => $c['handle'] ?? '',
 					'branch'      => $c['branch'] ?? '',
+					'age_days'    => $c['age_days'] ?? '',
+					'size'        => $this->format_bytes( $c['size_bytes'] ?? null ),
+					'artifacts'   => $this->format_bytes( $c['artifact_size_bytes'] ?? 0 ),
 					'signal'      => $c['signal'] ?? '',
 					'reason_code' => $c['reason_code'] ?? ( $c['signal'] ?? '' ),
 					'reason'      => $c['reason'] ?? '',
 				),
 				array_slice( $candidates, 0, $limit )
 			);
-			$fields         = $verbose ? array( 'handle', 'branch', 'signal', 'reason' ) : array( 'handle', 'branch', 'signal', 'reason_code' );
+			$fields         = $verbose ? array( 'handle', 'branch', 'age_days', 'size', 'artifacts', 'signal', 'reason' ) : array( 'handle', 'branch', 'age_days', 'size', 'artifacts', 'signal', 'reason_code' );
 			$this->format_items( $candidate_rows, $fields, array( 'format' => 'table' ), 'handle' );
 			$this->render_cleanup_truncation_hint( count( $candidates ), $limit, 'candidate rows' );
 		}
@@ -1518,13 +1566,16 @@ private function render_worktree_cleanup_result( array $result, array $assoc_arg
 				fn( $c ) => array(
 					'handle'      => $c['handle'] ?? '',
 					'branch'      => $c['branch'] ?? '',
+					'age_days'    => $c['age_days'] ?? '',
+					'size'        => $this->format_bytes( $c['size_bytes'] ?? null ),
+					'artifacts'   => $this->format_bytes( $c['artifact_size_bytes'] ?? 0 ),
 					'signal'      => $c['signal'] ?? '',
 					'reason_code' => $c['reason_code'] ?? ( $c['signal'] ?? '' ),
 					'reason'      => $c['reason'] ?? '',
 				),
 				array_slice( $removed, 0, $limit )
 			);
-			$fields       = $verbose ? array( 'handle', 'branch', 'signal', 'reason' ) : array( 'handle', 'branch', 'signal', 'reason_code' );
+			$fields       = $verbose ? array( 'handle', 'branch', 'age_days', 'size', 'artifacts', 'signal', 'reason' ) : array( 'handle', 'branch', 'age_days', 'size', 'artifacts', 'signal', 'reason_code' );
 			$this->format_items( $removed_rows, $fields, array( 'format' => 'table' ), 'handle' );
 			$this->render_cleanup_truncation_hint( count( $removed ), $limit, 'removed rows' );
 		}
@@ -1537,6 +1588,9 @@ private function render_worktree_cleanup_result( array $result, array $assoc_arg
 					'handle'       => $s['handle'] ?? '',
 					'reason_code'  => $s['reason_code'] ?? '',
 					'reason'       => $verbose ? ( $s['reason'] ?? '' ) : $this->shorten_cleanup_reason( (string) ( $s['reason'] ?? '' ) ),
+					'age_days'     => $s['age_days'] ?? '',
+					'size'         => $this->format_bytes( $s['size_bytes'] ?? null ),
+					'artifacts'    => $this->format_bytes( $s['artifact_size_bytes'] ?? 0 ),
 					'repo'         => $s['repo'] ?? '',
 					'branch'       => $s['branch'] ?? '',
 					'path'         => $s['path'] ?? '',
@@ -1546,7 +1600,7 @@ private function render_worktree_cleanup_result( array $result, array $assoc_arg
 				),
 				array_slice( $skipped, 0, $limit )
 			);
-			$fields       = $verbose ? array( 'handle', 'reason_code', 'reason', 'repo', 'branch', 'path', 'primary_path', 'missing', 'hint' ) : array( 'handle', 'reason_code', 'reason' );
+			$fields       = $verbose ? array( 'handle', 'reason_code', 'reason', 'age_days', 'size', 'artifacts', 'repo', 'branch', 'path', 'primary_path', 'missing', 'hint' ) : array( 'handle', 'reason_code', 'age_days', 'size', 'artifacts', 'reason' );
 			$this->format_items( $skipped_rows, $fields, array( 'format' => 'table' ), 'handle' );
 			$this->render_cleanup_truncation_hint( count( $skipped ), $limit, 'skipped rows' );
 		}
@@ -1672,6 +1726,30 @@ private function render_cleanup_truncation_hint( int $total, int $limit, string
 		WP_CLI::log( sprintf( 'Showing %d of %d %s. Re-run with --verbose for all rows or --only=<reason_code> to filter.', $limit, $total, $label ) );
 	}
 
+	/**
+	 * Format a byte count without depending on WordPress helpers in smoke tests.
+	 *
+	 * @param mixed $bytes Raw byte count.
+	 * @return string Human-readable size.
+	 */
+	private function format_bytes( mixed $bytes ): string {
+		if ( null === $bytes || '' === $bytes ) {
+			return '-';
+		}
+
+		$bytes      = max( 0, (float) $bytes );
+		$units      = array( 'B', 'KiB', 'MiB', 'GiB', 'TiB' );
+		$unit       = 0;
+		$unit_count = count( $units );
+		while ( $bytes >= 1024 && $unit < $unit_count - 1 ) {
+			$bytes /= 1024;
+			++$unit;
+		}
+
+		$precision = 0 === $unit ? 0 : 1;
+		return number_format( $bytes, $precision ) . ' ' . $units[ $unit ];
+	}
+
 	/**
 	 * Render the freshness block for `worktree add` results.
 	 *
diff --git a/inc/Workspace/Workspace.php b/inc/Workspace/Workspace.php
index 7821b6a..a9a4fa2 100644
--- a/inc/Workspace/Workspace.php
+++ b/inc/Workspace/Workspace.php
@@ -36,6 +36,11 @@ class Workspace {
 	 */
 	private const CLEANUP_GITHUB_MAX_PAGES = 3;
 
+	/**
+	 * Number of largest/oldest rows to expose in cleanup summaries.
+	 */
+	private const CLEANUP_SUMMARY_TOP_LIMIT = 10;
+
 	/**
 	 * @var string Resolved workspace path.
 	 */
@@ -1523,13 +1528,19 @@ public function worktree_list( ?string $repo = null, ?string $state = null ): ar
 					? 0
 					: count( array_filter( array_map( 'trim', explode( "\n", $dirty_result['output'] ?? '' ) ) ) );
 				$metadata     = ( ! $is_primary && $inside_ws ) ? WorktreeContextInjector::get_metadata( $relative ) : null;
+				$created_at   = is_array( $metadata ) ? ( $metadata['created_at'] ?? null ) : null;
+				$disk         = $this->build_worktree_disk_report( $primary, $wt['path'], ! $is_primary, $created_at, $metadata );
+				$stale_reason = $this->detect_worktree_stale_reason( ! $is_primary, $dirty_files, $disk['age_days'] ?? null, $created_at );
+				if ( null !== $stale_reason ) {
+					$disk['stale_reason'] = $stale_reason;
+				}
 
 				$lifecycle_state = is_array( $metadata ) ? ( $metadata['lifecycle_state'] ?? null ) : null;
 				if ( null !== $state && $lifecycle_state !== $state ) {
 					continue;
 				}
 
-				$worktrees[] = array(
+				$worktrees[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $primary,
 					'is_worktree' => ! $is_primary,
@@ -1540,12 +1551,12 @@ public function worktree_list( ?string $repo = null, ?string $state = null ): ar
 					'head'        => $wt['head'],
 					'path'        => $wt['path'],
 					'dirty'       => $dirty_files,
-					'created_at'  => is_array( $metadata ) ? ( $metadata['created_at'] ?? null ) : null,
+					'created_at'  => $created_at,
 					'lifecycle_state' => $lifecycle_state,
 					'pr_url'      => is_array( $metadata ) ? ( $metadata['pr_url'] ?? null ) : null,
 					'pr_number'   => is_array( $metadata ) ? ( $metadata['pr_number'] ?? null ) : null,
 					'metadata'    => $metadata,
-				);
+				), $disk );
 			}
 		}
 
@@ -1699,6 +1710,11 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 		$skip_github = ! empty( $opts['skip_github'] );
 		$apply_plan  = isset( $opts['apply_plan'] ) && is_array( $opts['apply_plan'] ) ? $opts['apply_plan'] : null;
 		$older_than  = isset( $opts['older_than'] ) ? trim( (string) $opts['older_than'] ) : '';
+		$sort        = isset( $opts['sort'] ) ? trim( (string) $opts['sort'] ) : '';
+
+		if ( '' !== $sort && ! in_array( $sort, array( 'size', 'age' ), true ) ) {
+			return new \WP_Error( 'invalid_cleanup_sort', 'Invalid cleanup sort. Use size or age.', array( 'status' => 400 ) );
+		}
 
 		$planned_candidates = null;
 		if ( null !== $apply_plan ) {
@@ -1755,10 +1771,11 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 			$wt_path      = $wt['path'] ?? '';
 			$metadata     = $wt['metadata'] ?? null;
 			$created_at   = $wt['created_at'] ?? null;
+			$disk_fields  = $this->extract_worktree_disk_fields( $wt );
 			$primary_path = '' !== $repo ? $this->get_primary_path( $repo ) : '';
 
 			if ( ! empty( $wt['external'] ) ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'       => $handle,
 					'reason_code'  => 'external_worktree',
 					'reason'       => 'external worktree (outside workspace)',
@@ -1770,7 +1787,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'primary_path' => $primary_path,
 					'created_at'   => $created_at,
 					'metadata'     => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
@@ -1789,7 +1806,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 						$missing_fields[] = $field;
 					}
 				}
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'         => $handle,
 					'repo'           => $repo,
 					'branch'         => $branch,
@@ -1800,12 +1817,12 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'hint'           => 'Run workspace worktree prune if this is a stale registry entry; inspect manually if the path still exists.',
 					'created_at'     => $created_at,
 					'metadata'       => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
 			if ( in_array( $branch, $protected_branches, true ) ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $repo,
 					'branch'      => $branch,
@@ -1814,12 +1831,12 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'reason'      => sprintf( 'protected branch (%s)', $branch ),
 					'created_at'  => $created_at,
 					'metadata'    => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
 			if ( $dirty_count > 0 && ! $force ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $repo,
 					'branch'      => $branch,
@@ -1829,7 +1846,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'dirty'       => $dirty_count,
 					'created_at'  => $created_at,
 					'metadata'    => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
@@ -1840,7 +1857,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 			// harder problem than dirty-file loss, and this guard is cheap.
 			$unpushed = $this->count_unpushed_commits( $wt_path );
 			if ( $unpushed > 0 ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $repo,
 					'branch'      => $branch,
@@ -1850,13 +1867,13 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'unpushed'    => $unpushed,
 					'created_at'  => $created_at,
 					'metadata'    => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
 			$primary_path = $this->get_primary_path( $repo );
 			if ( ! is_dir( $primary_path . '/.git' ) ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $repo,
 					'branch'      => $branch,
@@ -1866,7 +1883,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'hint'        => 'Run workspace worktree prune if this is a stale registry entry; inspect manually if the path still exists.',
 					'created_at'  => $created_at,
 					'metadata'    => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
@@ -1888,7 +1905,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 				$signal = $this->detect_merge_signal( $primary_path, $repo, $branch, $skip_github, $github_cache );
 			}
 			if ( null === $signal ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $repo,
 					'branch'      => $branch,
@@ -1897,12 +1914,12 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'reason'      => 'no merge signal — leaving in place',
 					'created_at'  => $created_at,
 					'metadata'    => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
 			if ( 'github-unknown' === ( $signal['signal'] ?? '' ) ) {
-				$skipped[] = array(
+				$skipped[] = array_merge( array(
 					'handle'      => $handle,
 					'repo'        => $repo,
 					'branch'      => $branch,
@@ -1911,7 +1928,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 					'reason'      => $signal['reason'],
 					'created_at'  => $created_at,
 					'metadata'    => $metadata,
-				);
+				), $disk_fields );
 				continue;
 			}
 
@@ -1920,7 +1937,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 				$created_ts = is_string( $created_at ) && '' !== $created_at ? strtotime( $created_at ) : false;
 				if ( false === $created_ts ) {
 					++$age_filter['unknown_age'];
-					$skipped[] = array(
+					$skipped[] = array_merge( array(
 						'handle'      => $handle,
 						'repo'        => $repo,
 						'branch'      => $branch,
@@ -1935,7 +1952,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 							'threshold'  => $age_filter['threshold'],
 							'decision'   => 'unknown_age',
 						),
-					);
+					), $disk_fields );
 					continue;
 				}
 
@@ -1950,7 +1967,7 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 
 				if ( $created_ts > $age_filter['threshold_unix'] ) {
 					++$age_filter['excluded'];
-					$skipped[] = array(
+					$skipped[] = array_merge( array(
 						'handle'      => $handle,
 						'repo'        => $repo,
 						'branch'      => $branch,
@@ -1960,14 +1977,14 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 						'created_at'  => $created_at,
 						'metadata'    => $metadata,
 						'age_filter'  => array_merge( $age_decision, array( 'decision' => 'excluded' ) ),
-					);
+					), $disk_fields );
 					continue;
 				}
 
 				$age_decision['decision'] = 'included';
 			}
 
-			$candidate = array(
+			$candidate = array_merge( array(
 				'handle'      => $wt['handle'],
 				'repo'        => $repo,
 				'branch'      => $branch,
@@ -1979,13 +1996,15 @@ public function worktree_cleanup_merged( array $opts = array() ): array|\WP_Erro
 				'pr_url'      => $signal['pr_url'] ?? null,
 				'created_at'  => $created_at,
 				'metadata'    => $metadata,
-			);
+			), $disk_fields );
 			if ( null !== $age_decision ) {
 				$candidate['age_filter'] = $age_decision;
 			}
 			$candidates[] = $candidate;
 		}
 
+		$candidates = $this->sort_worktree_cleanup_rows( $candidates, $sort );
+
 		if ( null !== $planned_candidates ) {
 			$scoped     = $this->scope_worktree_cleanup_to_plan( $planned_candidates, $candidates, $skipped );
 			$candidates = $scoped['candidates'];
@@ -2034,6 +2053,7 @@ function () use ( $cand, $force ) {
 					'reason'      => 'remove failed: ' . $remove->get_error_message(),
 					'created_at'  => $cand['created_at'] ?? null,
 					'metadata'    => $cand['metadata'] ?? null,
+					'size_bytes'  => $cand['size_bytes'] ?? null,
 				);
 				continue;
 			}
@@ -2064,6 +2084,11 @@ function () use ( $cand, $force ) {
 	private function build_worktree_cleanup_summary( array $candidates, array $removed, array $skipped, ?array $age_filter = null ): array {
 		$skipped_by_reason    = array();
 		$candidates_by_signal = array();
+		$size_by_repo         = array();
+		$artifact_by_repo     = array();
+		$total_size_bytes     = 0;
+		$total_artifact_bytes = 0;
+		$all_rows             = array_merge( $candidates, $removed, $skipped );
 
 		foreach ( $skipped as $row ) {
 			$code                       = (string) ( $row['reason_code'] ?? 'unknown' );
@@ -2075,15 +2100,38 @@ private function build_worktree_cleanup_summary( array $candidates, array $remov
 			$candidates_by_signal[ $signal ] = ( $candidates_by_signal[ $signal ] ?? 0 ) + 1;
 		}
 
+		foreach ( $all_rows as $row ) {
+			$repo           = (string) ( $row['repo'] ?? 'unknown' );
+			$size_bytes     = isset( $row['size_bytes'] ) ? (int) $row['size_bytes'] : 0;
+			$artifact_bytes = isset( $row['artifact_size_bytes'] ) ? (int) $row['artifact_size_bytes'] : 0;
+
+			if ( $size_bytes > 0 ) {
+				$size_by_repo[ $repo ] = ( $size_by_repo[ $repo ] ?? 0 ) + $size_bytes;
+				$total_size_bytes     += $size_bytes;
+			}
+			if ( $artifact_bytes > 0 ) {
+				$artifact_by_repo[ $repo ] = ( $artifact_by_repo[ $repo ] ?? 0 ) + $artifact_bytes;
+				$total_artifact_bytes     += $artifact_bytes;
+			}
+		}
+
 		ksort( $skipped_by_reason );
 		ksort( $candidates_by_signal );
+		arsort( $size_by_repo );
+		arsort( $artifact_by_repo );
 
 		$summary = array(
-			'would_remove'         => count( $candidates ),
-			'removed'              => count( $removed ),
-			'skipped'              => count( $skipped ),
-			'skipped_by_reason'    => $skipped_by_reason,
-			'candidates_by_signal' => $candidates_by_signal,
+			'would_remove'          => count( $candidates ),
+			'removed'               => count( $removed ),
+			'skipped'               => count( $skipped ),
+			'skipped_by_reason'     => $skipped_by_reason,
+			'candidates_by_signal'  => $candidates_by_signal,
+			'total_size_bytes'      => $total_size_bytes,
+			'artifact_size_bytes'   => $total_artifact_bytes,
+			'size_by_repo'          => $size_by_repo,
+			'artifact_size_by_repo' => $artifact_by_repo,
+			'top_by_size'           => $this->summarize_top_worktree_rows( $all_rows, 'size_bytes' ),
+			'top_by_age'            => $this->summarize_top_worktree_rows( $all_rows, 'age_days' ),
 		);
 
 		if ( null !== $age_filter ) {
@@ -2094,6 +2142,268 @@ private function build_worktree_cleanup_summary( array $candidates, array $remov
 		return $summary;
 	}
 
+	/**
+	 * Determine a non-destructive stale reason for list/reporting surfaces.
+	 *
+	 * @param bool        $is_worktree Whether the row is a worktree.
+	 * @param int         $dirty_files Dirty file count.
+	 * @param int|null    $age_days    Whole-day age.
+	 * @param string|null $created_at  Lifecycle timestamp.
+	 * @return string|null Stale reason code.
+	 */
+	private function detect_worktree_stale_reason( bool $is_worktree, int $dirty_files, ?int $age_days, ?string $created_at ): ?string {
+		if ( ! $is_worktree ) {
+			return null;
+		}
+
+		if ( $dirty_files > 0 ) {
+			return 'dirty';
+		}
+
+		if ( null === $created_at || '' === $created_at || null === $age_days ) {
+			return 'missing_metadata';
+		}
+
+		$threshold = (int) apply_filters( 'datamachine_code_worktree_stale_days', 14 );
+		if ( $threshold > 0 && $age_days >= $threshold ) {
+			return 'older_than_threshold';
+		}
+
+		return null;
+	}
+
+	/**
+	 * Build disk and artifact metadata for a worktree/list row.
+	 *
+	 * @param string      $repo        Primary repo name.
+	 * @param string      $path        Worktree path.
+	 * @param bool        $is_worktree Whether the row is a linked worktree.
+	 * @param string|null $created_at Lifecycle creation timestamp.
+	 * @param array|null $metadata    Stored lifecycle/context metadata.
+	 * @return array<string,mixed>
+	 */
+	private function build_worktree_disk_report( string $repo, string $path, bool $is_worktree, ?string $created_at, ?array $metadata ): array {
+		$size_bytes      = $this->estimate_path_size_bytes( $path );
+		$last_touched_at = $this->detect_worktree_last_touched_at( $path, $metadata, $created_at );
+		$age_days        = $this->calculate_age_days( $created_at );
+		$artifacts       = $is_worktree ? $this->detect_worktree_artifacts( $repo, $path ) : array();
+		$artifact_bytes  = array_sum( array_map( fn( $artifact ) => (int) ( $artifact['size_bytes'] ?? 0 ), $artifacts ) );
+
+		return array(
+			'size_bytes'           => $size_bytes,
+			'estimated_size_bytes' => $size_bytes,
+			'last_touched_at'      => $last_touched_at,
+			'age_days'             => $age_days,
+			'artifacts'            => $artifacts,
+			'artifact_size_bytes'  => $artifact_bytes,
+		);
+	}
+
+	/**
+	 * Pull disk fields from an existing worktree row for cleanup output.
+	 *
+	 * @param array $wt Worktree row.
+	 * @return array<string,mixed>
+	 */
+	private function extract_worktree_disk_fields( array $wt ): array {
+		return array(
+			'size_bytes'           => $wt['size_bytes'] ?? null,
+			'estimated_size_bytes' => $wt['estimated_size_bytes'] ?? ( $wt['size_bytes'] ?? null ),
+			'last_touched_at'      => $wt['last_touched_at'] ?? null,
+			'age_days'             => $wt['age_days'] ?? null,
+			'stale_reason'         => $wt['stale_reason'] ?? null,
+			'artifacts'            => $wt['artifacts'] ?? array(),
+			'artifact_size_bytes'  => $wt['artifact_size_bytes'] ?? 0,
+		);
+	}
+
+	/**
+	 * Estimate a path's on-disk size using the platform's fast `du` primitive.
+	 *
+	 * @param string $path Path to inspect.
+	 * @return int|null Size in bytes, or null when unavailable.
+	 */
+	private function estimate_path_size_bytes( string $path ): ?int {
+		if ( '' === $path || ( ! file_exists( $path ) && ! is_link( $path ) ) ) {
+			return null;
+		}
+
+		$output = array();
+		$code   = 1;
+		// phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.system_calls_exec
+		exec( sprintf( 'du -sk %s 2>/dev/null', escapeshellarg( $path ) ), $output, $code );
+		if ( 0 !== $code || empty( $output[0] ) ) {
+			return null;
+		}
+
+		$parts = preg_split( '/\s+/', trim( (string) $output[0] ) );
+		$kb    = isset( $parts[0] ) && ctype_digit( $parts[0] ) ? (int) $parts[0] : 0;
+		return $kb > 0 ? $kb * 1024 : 0;
+	}
+
+	/**
+	 * Detect non-source artifact directories worth reporting separately.
+	 *
+	 * @param string $repo Repo name.
+	 * @param string $path Worktree path.
+	 * @return array<int,array<string,mixed>> Artifact rows.
+	 */
+	private function detect_worktree_artifacts( string $repo, string $path ): array {
+		$patterns = $this->get_worktree_artifact_profile( $repo, $path );
+		$rows     = array();
+
+		foreach ( $patterns as $relative => $label ) {
+			$relative = trim( (string) $relative, '/' );
+			if ( '' === $relative || str_contains( $relative, '..' ) ) {
+				continue;
+			}
+
+			$artifact_path = rtrim( $path, '/' ) . '/' . $relative;
+			if ( ! is_dir( $artifact_path ) ) {
+				continue;
+			}
+
+			$size   = $this->estimate_path_size_bytes( $artifact_path );
+			$rows[] = array(
+				'path'       => $relative,
+				'label'      => (string) $label,
+				'size_bytes' => $size,
+			);
+		}
+
+		usort( $rows, fn( $a, $b ) => (int) ( $b['size_bytes'] ?? 0 ) <=> (int) ( $a['size_bytes'] ?? 0 ) );
+		return $rows;
+	}
+
+	/**
+	 * Resolve repo-specific artifact profile paths.
+	 *
+	 * @param string $repo Repo name.
+	 * @param string $path Worktree path.
+	 * @return array<string,string> Relative path => label map.
+	 */
+	private function get_worktree_artifact_profile( string $repo, string $path ): array {
+		$profile = array();
+
+		if ( is_file( rtrim( $path, '/' ) . '/Cargo.toml' ) || 'homeboy' === $repo ) {
+			$profile['target'] = 'Rust build artifacts';
+		}
+
+		if ( is_file( rtrim( $path, '/' ) . '/package.json' ) ) {
+			$profile['node_modules'] = 'Node dependencies';
+			$profile['.next']        = 'Next.js build cache';
+			$profile['dist']         = 'JavaScript build output';
+			$profile['coverage']     = 'test coverage output';
+		}
+
+		if ( is_file( rtrim( $path, '/' ) . '/composer.json' ) ) {
+			$profile['vendor'] = 'Composer dependencies';
+		}
+
+		/**
+		 * Filters non-source artifact paths reported for a workspace worktree.
+		 *
+		 * Reporting is non-destructive. Future cleanup actions should reuse this
+		 * profile but add separate opt-in delete gates.
+		 *
+		 * @param array<string,string> $profile Relative path => label map.
+		 * @param string               $repo    Repo name.
+		 * @param string               $path    Worktree path.
+		 */
+		$filtered = apply_filters( 'datamachine_code_worktree_artifact_profile', $profile, $repo, $path );
+		return is_array( $filtered ) ? $filtered : $profile;
+	}
+
+	/**
+	 * Resolve the most useful last-touched timestamp for a worktree.
+	 *
+	 * @param string      $path       Worktree path.
+	 * @param array|null  $metadata   Stored lifecycle/context metadata.
+	 * @param string|null $created_at Created timestamp fallback.
+	 * @return string|null ISO timestamp.
+	 */
+	private function detect_worktree_last_touched_at( string $path, ?array $metadata, ?string $created_at ): ?string {
+		foreach ( array( 'last_touched_at', 'updated_at', 'timestamp' ) as $key ) {
+			if ( is_array( $metadata ) && ! empty( $metadata[ $key ] ) && false !== strtotime( (string) $metadata[ $key ] ) ) {
+				return gmdate( 'c', (int) strtotime( (string) $metadata[ $key ] ) );
+			}
+		}
+
+		$git_marker = rtrim( $path, '/' ) . '/.git';
+		$mtime      = file_exists( $git_marker ) ? filemtime( $git_marker ) : false;
+		if ( false === $mtime && file_exists( $path ) ) {
+			$mtime = filemtime( $path );
+		}
+
+		if ( false !== $mtime ) {
+			return gmdate( 'c', (int) $mtime );
+		}
+
+		return $created_at;
+	}
+
+	/**
+	 * Calculate whole-day age from an ISO timestamp.
+	 *
+	 * @param string|null $created_at Created timestamp.
+	 * @return int|null Whole days old, or null when unknown.
+	 */
+	private function calculate_age_days( ?string $created_at ): ?int {
+		if ( null === $created_at || '' === $created_at ) {
+			return null;
+		}
+
+		$created_ts = strtotime( $created_at );
+		if ( false === $created_ts ) {
+			return null;
+		}
+
+		return max( 0, (int) floor( ( time() - $created_ts ) / 86400 ) );
+	}
+
+	/**
+	 * Sort cleanup rows by requested reporting dimension.
+	 *
+	 * @param array<int,array> $rows Rows to sort.
+	 * @param string           $sort size|age|empty.
+	 * @return array<int,array>
+	 */
+	private function sort_worktree_cleanup_rows( array $rows, string $sort ): array {
+		if ( 'size' === $sort ) {
+			usort( $rows, fn( $a, $b ) => (int) ( $b['size_bytes'] ?? 0 ) <=> (int) ( $a['size_bytes'] ?? 0 ) );
+		} elseif ( 'age' === $sort ) {
+			usort( $rows, fn( $a, $b ) => (int) ( $b['age_days'] ?? -1 ) <=> (int) ( $a['age_days'] ?? -1 ) );
+		}
+
+		return $rows;
+	}
+
+	/**
+	 * Produce compact top-N rows for cleanup summaries.
+	 *
+	 * @param array<int,array> $rows Rows to summarize.
+	 * @param string           $field Numeric field to sort by.
+	 * @return array<int,array<string,mixed>>
+	 */
+	private function summarize_top_worktree_rows( array $rows, string $field ): array {
+		$rows = array_values( array_filter( $rows, fn( $row ) => isset( $row[ $field ] ) && null !== $row[ $field ] && (int) $row[ $field ] > 0 ) );
+		usort( $rows, fn( $a, $b ) => (int) ( $b[ $field ] ?? 0 ) <=> (int) ( $a[ $field ] ?? 0 ) );
+
+		return array_map(
+			fn( $row ) => array(
+				'handle'              => $row['handle'] ?? '',
+				'repo'                => $row['repo'] ?? '',
+				'branch'              => $row['branch'] ?? '',
+				'path'                => $row['path'] ?? '',
+				'size_bytes'          => $row['size_bytes'] ?? null,
+				'artifact_size_bytes' => $row['artifact_size_bytes'] ?? 0,
+				'age_days'            => $row['age_days'] ?? null,
+				'reason_code'         => $row['reason_code'] ?? '',
+			),
+			array_slice( $rows, 0, self::CLEANUP_SUMMARY_TOP_LIMIT )
+		);
+	}
+
 	/**
 	 * Parse a compact cleanup age duration.
 	 *
@@ -2181,11 +2491,11 @@ private function scope_worktree_cleanup_to_plan( array $planned_candidates, arra
 		$scoped_skipped    = array();
 
 		foreach ( $planned_candidates as $plan_row ) {
-			$handle = (string) ( $plan_row['handle'] ?? '' );
+			$handle  = (string) ( $plan_row['handle'] ?? '' );
 			$current = $current_by_handle[ $handle ] ?? null;
 
 			if ( null === $current ) {
-				$skip = $skipped_by_handle[ $handle ] ?? array(
+				$skip                   = $skipped_by_handle[ $handle ] ?? array(
 					'handle'      => $handle,
 					'repo'        => (string) ( $plan_row['repo'] ?? '' ),
 					'branch'      => (string) ( $plan_row['branch'] ?? '' ),
@@ -2366,7 +2676,7 @@ private function detect_merge_signal( string $primary_path, string $repo, string
 			return null;
 		}
 
-		$pr = $this->find_merged_pr_for_branch( $gh_slug, $branch, $github_cache );
+		$pr = $this->find_closed_pr_for_branch( $gh_slug, $branch, $github_cache );
 		if ( is_wp_error( $pr ) ) {
 			return array(
 				'signal' => 'github-unknown',
@@ -2377,9 +2687,17 @@ private function detect_merge_signal( string $primary_path, string $repo, string
 			return null;
 		}
 
+		if ( ! empty( $pr['merged_at'] ) ) {
+			return array(
+				'signal' => 'pr-merged',
+				'reason' => sprintf( 'PR #%d merged (%s)', $pr['number'], $pr['state'] ),
+				'pr_url' => $pr['html_url'] ?? null,
+			);
+		}
+
 		return array(
-			'signal' => 'pr-merged',
-			'reason' => sprintf( 'PR #%d merged (%s)', $pr['number'], $pr['state'] ),
+			'signal' => 'pr-closed',
+			'reason' => sprintf( 'PR #%d closed without merge', $pr['number'] ),
 			'pr_url' => $pr['html_url'] ?? null,
 		);
 	}
@@ -2452,7 +2770,7 @@ private function resolve_github_slug( string $primary_path ): ?string {
 	}
 
 	/**
-	 * Look up a merged PR for a branch via a cached GitHub API snapshot.
+	 * Look up a closed PR for a branch via a cached GitHub API snapshot.
 	 *
 	 * Cleanup may inspect hundreds of worktrees for the same repo. Querying
 	 * GitHub once per branch does not scale, so each repo gets one bounded
@@ -2463,7 +2781,7 @@ private function resolve_github_slug( string $primary_path ): ?string {
 	 * @param array  $github_cache Run-local cache keyed by owner/repo.
 	 * @return array|null|\WP_Error PR data, null when no PR matched, or lookup failure.
 	 */
-	private function find_merged_pr_for_branch( string $slug, string $branch, array &$github_cache = array() ): array|\WP_Error|null {
+	private function find_closed_pr_for_branch( string $slug, string $branch, array &$github_cache = array() ): array|\WP_Error|null {
 		$lookup = $this->get_cleanup_github_lookup( $slug, $github_cache );
 		if ( is_wp_error( $lookup ) ) {
 			return $lookup;
@@ -2477,7 +2795,7 @@ private function find_merged_pr_for_branch( string $slug, string $branch, array
 	}
 
 	/**
-	 * Load and cache merged same-repo PRs for a GitHub repo.
+	 * Load and cache closed same-repo PRs for a GitHub repo.
 	 *
 	 * @param string $slug         owner/repo.
 	 * @param array  $github_cache Run-local cache keyed by owner/repo.
@@ -2506,7 +2824,7 @@ private function get_cleanup_github_lookup( string $slug, array &$github_cache )
 			return null;
 		}
 
-		$merged = array();
+		$closed = array();
 		$url    = GitHubRemote::apiUrl( $slug, 'pulls' );
 
 		for ( $page = 1; $page <= self::CLEANUP_GITHUB_MAX_PAGES; $page++ ) {
@@ -2535,10 +2853,6 @@ private function get_cleanup_github_lookup( string $slug, array &$github_cache )
 
 			$items = (array) ( $response['data'] ?? array() );
 			foreach ( $items as $pr ) {
-				if ( empty( $pr['merged_at'] ) ) {
-					continue;
-				}
-
 				$head      = is_array( $pr['head'] ?? null ) ? $pr['head'] : array();
 				$head_repo = is_array( $head['repo'] ?? null ) ? (string) ( $head['repo']['full_name'] ?? '' ) : '';
 				$head_ref  = (string) ( $head['ref'] ?? '' );
@@ -2546,10 +2860,10 @@ private function get_cleanup_github_lookup( string $slug, array &$github_cache )
 					continue;
 				}
 
-				$merged[ $head_ref ] = array(
+				$closed[ $head_ref ] = array(
 					'number'    => (int) ( $pr['number'] ?? 0 ),
 					'state'     => (string) ( $pr['state'] ?? 'closed' ),
-					'merged_at' => (string) $pr['merged_at'],
+					'merged_at' => (string) ( $pr['merged_at'] ?? '' ),
 					'html_url'  => (string) ( $pr['html_url'] ?? '' ),
 				);
 			}
@@ -2559,8 +2873,8 @@ private function get_cleanup_github_lookup( string $slug, array &$github_cache )
 			}
 		}
 
-		$github_cache[ $slug ] = $merged;
-		return $merged;
+		$github_cache[ $slug ] = $closed;
+		return $closed;
 	}
 
 	/**
diff --git a/tests/smoke-worktree-cleanup-cli.php b/tests/smoke-worktree-cleanup-cli.php
index a0d6403..f015532 100644
--- a/tests/smoke-worktree-cleanup-cli.php
+++ b/tests/smoke-worktree-cleanup-cli.php
@@ -76,6 +76,9 @@ function datamachine_code_cleanup_report(): array {
 				'repo'        => 'repo',
 				'branch'      => 'feature-' . $i,
 				'path'        => '/workspace/repo@feature-' . $i,
+				'age_days'    => 20 + $i,
+				'size_bytes'          => 1024 * 1024 * $i,
+				'artifact_size_bytes' => 512 * 1024 * $i,
 				'reason_code' => 1 === $i ? 'dirty_worktree' : 'no_merge_signal',
 				'reason'      => 1 === $i ? 'working tree dirty (1 files) - pass force=true to override' : 'no merge signal - leaving in place',
 			);
@@ -86,10 +89,12 @@ function datamachine_code_cleanup_report(): array {
 			'repo'           => '',
 			'branch'         => '',
 			'path'           => '',
-			'reason_code'    => 'missing_metadata',
-			'reason'         => 'missing repo/branch/path',
-			'missing_fields' => array( 'repo', 'branch', 'path' ),
-			'hint'           => 'Run workspace worktree prune if this is a stale registry entry; inspect manually if the path still exists.',
+			'reason_code'         => 'missing_metadata',
+			'reason'              => 'missing repo/branch/path',
+			'missing_fields'      => array( 'repo', 'branch', 'path' ),
+			'hint'                => 'Run workspace worktree prune if this is a stale registry entry; inspect manually if the path still exists.',
+			'size_bytes'          => 0,
+			'artifact_size_bytes' => 0,
 		);
 
 		return array(
@@ -101,6 +106,9 @@ function datamachine_code_cleanup_report(): array {
 					'repo'        => 'repo',
 					'branch'      => 'merged',
 					'path'        => '/workspace/repo@merged',
+					'age_days'    => 42,
+					'size_bytes'          => 4 * 1024 * 1024 * 1024,
+					'artifact_size_bytes' => 3 * 1024 * 1024 * 1024,
 					'signal'      => 'upstream-gone',
 					'reason_code' => 'upstream-gone',
 					'reason'      => 'remote branch deleted (likely merged + auto-deleted)',
@@ -120,6 +128,10 @@ function datamachine_code_cleanup_report(): array {
 				'candidates_by_signal' => array(
 					'upstream-gone' => 1,
 				),
+				'total_size_bytes'      => 10 * 1024 * 1024 * 1024,
+				'artifact_size_bytes'   => 7 * 1024 * 1024 * 1024,
+				'size_by_repo'          => array( 'repo' => 10 * 1024 * 1024 * 1024 ),
+				'artifact_size_by_repo' => array( 'repo' => 7 * 1024 * 1024 * 1024 ),
 			),
 		);
 	}
@@ -144,14 +156,70 @@ public function execute( array $input ): array {
 		}
 	}
 
+	class FakeListAbility {
+		public function execute( array $input ): array { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
+			return array(
+				'success'   => true,
+				'worktrees' => array(
+					array(
+						'handle'      => 'repo',
+						'repo'        => 'repo',
+						'is_primary'  => true,
+						'branch'      => 'main',
+						'head'        => 'abcdef123',
+						'dirty'       => 0,
+						'path'        => '/workspace/repo',
+					),
+					array(
+						'handle'              => 'repo@old',
+						'repo'                => 'repo',
+						'is_primary'          => false,
+						'branch'              => 'old',
+						'head'                => 'abcdef456',
+						'dirty'               => 0,
+						'created_at'          => '2026-04-01T00:00:00+00:00',
+						'age_days'            => 28,
+						'size_bytes'          => 4 * 1024 * 1024,
+						'artifact_size_bytes' => 3 * 1024 * 1024,
+						'artifacts'           => array( array( 'path' => 'target', 'size_bytes' => 3 * 1024 * 1024 ) ),
+						'stale_reason'        => 'older_than_threshold',
+						'path'                => '/workspace/repo@old',
+					),
+					array(
+						'handle'              => 'repo@dirty',
+						'repo'                => 'repo',
+						'is_primary'          => false,
+						'branch'              => 'dirty',
+						'head'                => 'abcdef789',
+						'dirty'               => 1,
+						'age_days'            => null,
+						'size_bytes'          => 1024,
+						'artifact_size_bytes' => 0,
+						'artifacts'           => array(),
+						'stale_reason'        => 'dirty',
+						'path'                => '/workspace/repo@dirty',
+					),
+				),
+			);
+		}
+	}
+
 	echo "=== smoke-worktree-cleanup-cli ===\n";
 
 	$ability = new FakeCleanupAbility();
+	$list_ability = new FakeListAbility();
 	$GLOBALS['__abilities'] = array(
 		'datamachine/workspace-worktree-cleanup' => $ability,
+		'datamachine/workspace-worktree-list'    => $list_ability,
 	);
 	$command = new \DataMachineCode\Cli\Commands\WorkspaceCommand();
 
+	echo "\n[0] list stale output exposes disk fields\n";
+	WP_CLI::$logs      = array();
+	WP_CLI::$successes = array();
+	$command->worktree( array( 'list' ), array( 'stale' => true ) );
+	datamachine_code_cleanup_assert( in_array( 'table:2:handle,repo,kind,branch,head,dirty,state,created_at,pr,age_days,size,artifacts,stale,path', WP_CLI::$logs, true ), 'worktree list --stale filters to stale rows and includes disk fields' );
+
 	echo "\n[1] JSON output is one parseable document\n";
 	WP_CLI::$logs      = array();
 	WP_CLI::$successes = array();
@@ -188,8 +256,9 @@ public function execute( array $input ): array {
 	WP_CLI::$successes = array();
 	$command->worktree( array( 'cleanup' ), array( 'dry-run' => true, 'skip-github' => true ) );
 	datamachine_code_cleanup_assert( 'Summary:' === ( WP_CLI::$logs[0] ?? '' ), 'human output starts with summary' );
-	datamachine_code_cleanup_assert( in_array( 'table:1:handle,branch,signal,reason_code', WP_CLI::$logs, true ), 'default candidate table uses compact fields' );
-	datamachine_code_cleanup_assert( in_array( 'table:10:handle,reason_code,reason', WP_CLI::$logs, true ), 'default skipped table omits path and hint fields' );
+	datamachine_code_cleanup_assert( in_array( 'table:1:handle,branch,age_days,size,artifacts,signal,reason_code', WP_CLI::$logs, true ), 'default candidate table uses compact disk fields' );
+	datamachine_code_cleanup_assert( in_array( 'table:10:handle,reason_code,age_days,size,artifacts,reason', WP_CLI::$logs, true ), 'default skipped table omits path and hint fields but keeps disk fields' );
+	datamachine_code_cleanup_assert( in_array( 'Top repos by worktree size:', WP_CLI::$logs, true ), 'human output includes top repo size summary' );
 	datamachine_code_cleanup_assert( in_array( 'Showing 10 of 12 skipped rows. Re-run with --verbose for all rows or --only=<reason_code> to filter.', WP_CLI::$logs, true ), 'human output truncates skipped rows with hint' );
 	datamachine_code_cleanup_assert( 1 === count( WP_CLI::$successes ), 'human output keeps success suffix' );
 
@@ -197,8 +266,8 @@ public function execute( array $input ): array {
 	WP_CLI::$logs      = array();
 	WP_CLI::$successes = array();
 	$command->worktree( array( 'cleanup' ), array( 'dry-run' => true, 'skip-github' => true, 'verbose' => true ) );
-	datamachine_code_cleanup_assert( in_array( 'table:1:handle,branch,signal,reason', WP_CLI::$logs, true ), 'verbose candidate table keeps full reason field' );
-	datamachine_code_cleanup_assert( in_array( 'table:12:handle,reason_code,reason,repo,branch,path,primary_path,missing,hint', WP_CLI::$logs, true ), 'verbose skipped table keeps diagnostic fields' );
+	datamachine_code_cleanup_assert( in_array( 'table:1:handle,branch,age_days,size,artifacts,signal,reason', WP_CLI::$logs, true ), 'verbose candidate table keeps full reason field' );
+	datamachine_code_cleanup_assert( in_array( 'table:12:handle,reason_code,reason,age_days,size,artifacts,repo,branch,path,primary_path,missing,hint', WP_CLI::$logs, true ), 'verbose skipped table keeps diagnostic fields' );
 
 	echo "\n[4] --only filters rows while keeping full summary\n";
 	WP_CLI::$logs      = array();
@@ -227,7 +296,7 @@ public function execute( array $input ): array {
 	WP_CLI::$successes = array();
 	$command->worktree( array( 'cleanup' ), array( 'dry-run' => true, 'skip-github' => true, 'older-than' => '7d' ) );
 	datamachine_code_cleanup_assert( array( 'dry_run' => true, 'force' => false, 'skip_github' => true, 'older_than' => '7d' ) === $ability->last_input, 'older-than forwards to cleanup ability as older_than' );
-	datamachine_code_cleanup_assert( in_array( 'table:8:metric,count', WP_CLI::$logs, true ), 'age filter summary adds two summary rows' );
+	datamachine_code_cleanup_assert( in_array( 'table:10:metric,count', WP_CLI::$logs, true ), 'age filter and disk summary rows are rendered' );
 
 	WP_CLI::$logs      = array();
 	WP_CLI::$successes = array();
@@ -236,5 +305,11 @@ public function execute( array $input ): array {
 	datamachine_code_cleanup_assert( '7d' === ( $older_than_json['summary']['age_filter']['older_than'] ?? '' ), 'JSON summary exposes older_than filter value' );
 	datamachine_code_cleanup_assert( 2 === (int) ( $older_than_json['summary']['age_filter']['excluded'] ?? 0 ), 'JSON summary exposes age-filter excluded count' );
 
+	echo "\n[7] --sort forwards cleanup sorting field\n";
+	WP_CLI::$logs      = array();
+	WP_CLI::$successes = array();
+	$command->worktree( array( 'cleanup' ), array( 'dry-run' => true, 'skip-github' => true, 'sort' => 'size', 'format' => 'json' ) );
+	datamachine_code_cleanup_assert( 'size' === ( $ability->last_input['sort'] ?? null ), '--sort forwards to cleanup ability' );
+
 	echo "\nAll worktree cleanup CLI smoke tests passed.\n";
 }
diff --git a/tests/smoke-worktree-cleanup-github-cache.php b/tests/smoke-worktree-cleanup-github-cache.php
index 264c84f..7406526 100644
--- a/tests/smoke-worktree-cleanup-github-cache.php
+++ b/tests/smoke-worktree-cleanup-github-cache.php
@@ -125,7 +125,7 @@ function size_format( $bytes ): string {
 		echo "  ✗ {$message}\n";
 	};
 
-	$find = new \ReflectionMethod( Workspace::class, 'find_merged_pr_for_branch' );
+	$find = new \ReflectionMethod( Workspace::class, 'find_closed_pr_for_branch' );
 	$detect = new \ReflectionMethod( Workspace::class, 'detect_merge_signal' );
 	$workspace = new Workspace();
 	$run = function ( string $command, string $cwd = '' ): string {
@@ -165,20 +165,33 @@ function size_format( $bytes ): string {
 			'repo' => array( 'full_name' => 'someone/data-machine-code' ),
 		),
 	);
+	$closed_pr = array(
+		'number'    => 44,
+		'state'     => 'closed',
+		'merged_at' => null,
+		'html_url'  => 'https://github.com/Extra-Chill/data-machine-code/pull/44',
+		'head'      => array(
+			'ref'  => 'closed-branch',
+			'repo' => array( 'full_name' => 'Extra-Chill/data-machine-code' ),
+		),
+	);
 
 	echo "=== smoke-worktree-cleanup-github-cache ===\n";
 
 	echo "\n[1] one repo lookup is cached across branch checks\n";
 	GitHubAbilities::$pat       = 'test-token';
 	GitHubAbilities::$calls     = array();
-	GitHubAbilities::$responses = array( array( 'data' => array( $merged_pr, $fork_pr ) ) );
+	GitHubAbilities::$responses = array( array( 'data' => array( $merged_pr, $fork_pr, $closed_pr ) ) );
 	$cache = array();
 
 	$hit  = $find->invokeArgs( $workspace, array( 'Extra-Chill/data-machine-code', 'merged-branch', &$cache ) );
 	$miss = $find->invokeArgs( $workspace, array( 'Extra-Chill/data-machine-code', 'missing-branch', &$cache ) );
 	$fork = $find->invokeArgs( $workspace, array( 'Extra-Chill/data-machine-code', 'fork-branch', &$cache ) );
+	$closed = $find->invokeArgs( $workspace, array( 'Extra-Chill/data-machine-code', 'closed-branch', &$cache ) );
 
 	$assert( 42, $hit['number'] ?? null, 'merged same-repo branch is found' );
+	$assert( 44, $closed['number'] ?? null, 'closed same-repo branch is found' );
+	$assert( '', $closed['merged_at'] ?? null, 'closed unmerged PR keeps empty merged_at' );
 	$assert( null, $miss, 'missing branch returns null' );
 	$assert( null, $fork, 'fork branch with same ref is ignored' );
 	$assert( 1, count( GitHubAbilities::$calls ), 'GitHub API called once for three branch checks' );
diff --git a/tests/smoke-worktree-cleanup.php b/tests/smoke-worktree-cleanup.php
index f617afc..b8a93f6 100644
--- a/tests/smoke-worktree-cleanup.php
+++ b/tests/smoke-worktree-cleanup.php
@@ -185,7 +185,10 @@ function size_format( $bytes ): string {
 	$run( 'git config user.email test@example.com', $primary );
 	$run( 'git config user.name test', $primary );
 	file_put_contents( $primary . '/README.md', "demo\n" );
+	file_put_contents( $primary . '/Cargo.toml', "[package]\nname = \"demo\"\nversion = \"0.1.0\"\n" );
+	file_put_contents( $primary . '/.gitignore', "target/\n" );
 	$run( 'git add README.md && git commit -m init', $primary );
+	$run( 'git add Cargo.toml .gitignore && git commit -m tooling', $primary );
 	$run( 'git branch -M main', $primary );
 	$run( 'git push -u origin main', $primary );
 
@@ -226,6 +229,8 @@ function size_format( $bytes ): string {
 
 	// Dirty the dirty worktree.
 	file_put_contents( $tmp . '/demo@dirty-branch/scratch.txt', 'dirty' );
+	mkdir( $tmp . '/demo@merged-autodelete/target', 0755, true );
+	file_put_contents( $tmp . '/demo@merged-autodelete/target/artifact.bin', str_repeat( 'x', 4096 ) );
 
 	\DataMachineCode\Workspace\WorktreeContextInjector::store_metadata(
 		'demo@merged-autodelete',
@@ -293,6 +298,13 @@ function size_format( $bytes ): string {
 	$metadata_item  = array_values( $metadata_items )[0] ?? array();
 	$assert( '2026-04-25T00:00:00+00:00', $metadata_item['created_at'] ?? null, 'worktree list exposes creation metadata for agent runtime' );
 	$assert( 'agent-one', $metadata_item['metadata']['agent_slug'] ?? null, 'worktree list exposes agent metadata for agent runtime' );
+	$assert( true, isset( $metadata_item['size_bytes'] ), 'worktree list exposes estimated size bytes' );
+	$assert( true, isset( $metadata_item['age_days'] ), 'worktree list exposes age_days' );
+
+	$artifact_items = array_filter( $list['worktrees'] ?? array(), fn( $wt ) => ( $wt['handle'] ?? '' ) === 'demo@merged-autodelete' );
+	$artifact_item  = array_values( $artifact_items )[0] ?? array();
+	$assert( true, (int) ( $artifact_item['artifact_size_bytes'] ?? 0 ) > 0, 'worktree list reports Rust target artifact size' );
+	$assert( 'target', $artifact_item['artifacts'][0]['path'] ?? '', 'worktree list reports Rust target artifact path' );
 
 	$assert_contains( $plan['candidates'] ?? array(), 'demo@merged-autodelete', 'canonical merged worktree flagged prunable' );
 	$assert_contains( $plan['candidates'] ?? array(), 'demo@merged-recent', 'recent merged worktree is still prunable without age filter' );
@@ -320,6 +332,21 @@ function size_format( $bytes ): string {
 	$assert( 4, (int) ( $plan['summary']['would_remove'] ?? 0 ), 'summary counts cleanup candidates' );
 	$assert( 1, (int) ( $plan['summary']['skipped_by_reason']['dirty_worktree'] ?? 0 ), 'summary counts dirty skips by reason' );
 	$assert( true, isset( $plan['summary']['skipped_by_reason']['no_merge_signal'] ), 'summary includes no_merge_signal bucket' );
+	$assert( true, (int) ( $plan['summary']['total_size_bytes'] ?? 0 ) > 0, 'summary reports total worktree size bytes' );
+	$assert( true, (int) ( $plan['summary']['artifact_size_bytes'] ?? 0 ) > 0, 'summary reports artifact size bytes' );
+	$assert( true, ! empty( $plan['summary']['top_by_size'] ), 'summary reports top worktrees by size' );
+
+	$size_plan = $ws->worktree_cleanup_merged(
+		array(
+			'dry_run'     => true,
+			'skip_github' => true,
+			'sort'        => 'size',
+		)
+	);
+	$assert( true, ! is_wp_error( $size_plan ) && ( $size_plan['success'] ?? false ), 'size-sorted dry_run returns success' );
+	$first_size = (int) ( $size_plan['candidates'][0]['size_bytes'] ?? 0 );
+	$second_size = (int) ( $size_plan['candidates'][1]['size_bytes'] ?? 0 );
+	$assert( true, $first_size >= $second_size, 'sort=size orders cleanup candidates by size descending' );
 
 	$age_plan = $ws->worktree_cleanup_merged(
 		array(