Improve a skill through analysis, targeted changes, and optimization. Supports both project skills (a ./skills/ directory) and installed skills.

Use the minimal framework and requirements checklist in this skill's criteria.md (same folder). If framework/REQUIREMENTS.md and framework/FRAMEWORK.md are available in the current project, read them too.

Phase 1 — Brainstorm

1. Identify target

Determine which skill to improve and where it lives (project vs installed).

•If the user names one, use it.
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Otherwise, scan for skills and ask which one:
- •If ./skills/ exists in the current project/workspace, scan that.
- •Otherwise, scan installed skills in ~/.claude/skills/.
•Ignore machine-managed folders like .backups/ when scanning.
•Do not target skills-improve itself.

2. Read and analyze

Read the skill's folder: SKILL.md, and any criteria.md, template.md, pending-updates.md, or other relevant files present. Ignore machine-managed artifacts like .backups/ and .skillstate.json unless they are directly relevant to the user's request.

Assess against the improvement dimensions in this skill's criteria.md (same folder). For each dimension, generate specific, actionable suggestions tied to what you actually read — not generic advice. Reference specific steps or sections.

3. Present suggestions

If AskUserQuestion is available, use it with multiSelect: true. Otherwise, present suggestions conversationally and let the user respond in plain language.

•Number each suggestion.
•For each: what to change, why it matters, which file(s) it touches.
•Group by dimension.

The user may select improvements, ask follow-up questions, or add their own ideas. If the user selects none, skip to Phase 3 (Optimize).

Phase 2 — Implement

4. Preview

For each selected improvement, show what will change:

•Which file(s) will be modified or created.
•A plain-language summary of the change.

Proceed only after the user confirms.

5. Backup

Before modifying files, create a timestamped backup:

•Create {skill_folder}/.backups/{filesystem-safe-timestamp}/ (use an ISO-8601 timestamp with : replaced by .).
•Record a list of the files that exist before changes (exclude .backups/) so rollback can remove newly created files.
•Copy all files that will change into the backup folder.

6. Apply selected improvements

•Preserve existing structure and voice.
•If an improvement requires a new file (e.g. extracting criteria into criteria.md), create it.
•Update last-updated in SKILL.md frontmatter to current UTC timestamp (ISO-8601).

7. Verify

Check that the modified skill is still well-formed:

•SKILL.md frontmatter is valid YAML.
•All files that existed before still exist.
•No broken references to other files or skills.

8. Rollback if needed

If verification fails:

•Restore all files from the backup created in step 5.
•Delete any newly created files that were not present in the pre-change file list (excluding .backups/ itself).
•Inform the user: "The improvements didn't apply cleanly. I've restored the skill to its previous state."
•Skip to step 13 (Summary) to report what went wrong. Do not run /skills-review in this case.

Phase 3 — Optimize

9. Optimize for conciseness

Re-read the improved skill. Assess against the optimization checklist in this skill's criteria.md.

10. Present optimization proposals

Show the user what you would tighten, with before/after for significant changes.

Ask for confirmation. If declined, skip to Phase 4.

11. Apply optimizations

Apply confirmed optimizations. Update last-updated.

Phase 4 — Review

12. Run skills-review

Invoke /skills-review on the improved skill.

13. Summary

Report:

•What was improved and why.
•Approximate token count change (if optimization was applied).
•Any review findings that need attention.