Conciseness

The ~450-word opening paragraph restates the --landed/--remove mode, patch-saving, and KEEP-rule details that steps 3–4 repeat, and the relentless run-on clause chains (e.g. "It keeps a worktree git does not list, a locked one, one outside the folders agents make worktrees in...") could be materially tightened — mostly efficient but with real duplication, fitting anchor 3 rather than 4's minor trimming.

Actionability

Every step carries an executable command — `df -h <checkout>`, `node <this skill>/scripts/scan.mjs --repo . --sessions <file>`, `git worktree remove --force`, `git worktree lock --reason "<why>" <path>`, `next telemetry disable` — and the decision logic is delegated to a real bundled script, with the telemetry edge case given a concrete PID/command diagnostic.

Workflow Clarity

Steps 1–6 are clearly sequenced with explicit validation for this destructive batch operation: the session list is re-saved and items re-judged right before --delete, "a failed removal turns that row into ASK", ASK rows require owner confirmation, and df is recorded before and after to verify the outcome — feedback loops are present, so the destructive-operation cap does not apply.

Progressive Disclosure

The verdict logic is properly externalized to scripts/scan.mjs (a real file, clearly referenced), but the SKILL.md body is a ~1,700-word wall of prose with no section headers, and the ~700 words of KEEP/SAFE/ASK policy in step 3 are reference material that could live in a separate file — matching anchor 3's inlined-should-be-separate content rather than 4's minor organization gaps.

Specificity

"removing the git worktrees and Next.js cache folders nothing uses, keeping every worktree a session or process works in and every cache a running server holds" lists several concrete actions with explicit preservation conditions, but omits the run-folders/artifacts category the skill also handles — a minor coverage gap that fits anchor 4 rather than the comprehensive coverage of 5.

Completeness

The what is explicit ("Free disk in a project by removing the git worktrees and Next.js cache folders nothing uses...") and the when is an explicit "Use for..." clause with concrete trigger phrases and a session-start-hint condition, clearly matching the anchor-5 example pattern.

Trigger Term Quality

Six natural trigger phrasings are given — /cleanup, "clean up worktrees", "free disk space", "what's using my disk", "delete unused worktrees or builds" — covering command, imperative, and question forms a user would actually say, matching comprehensive coverage; not 4 because no common variant is obviously missing.

Distinctiveness Conflict Risk

The worktree/Next.js-cache niche is distinct and mostly clearly scoped, but the generic triggers "free disk space" and "what's using my disk" would also be claimed by a general disk-cleanup skill, giving minor overlap risk — anchor 4 rather than 5's minimal conflict risk.