Skill Improvement Methodology
Iteratively improve a Claude Code skill using the skill-reviewer agent until it meets quality standards.
Prerequisites
Requires the `plugin-dev` plugin which provides the `skill-reviewer` agent.
Verify it's enabled: run `/plugins` — `plugin-dev` should appear in the list. If missing, install from the Trail of Bits plugin repository.
Core Loop
- **Review** - Call skill-reviewer on the target skill
- **Categorize** - Parse issues by severity
- **Fix** - Address critical and major issues
- **Evaluate** - Check minor issues for validity before fixing
- **Repeat** - Continue until quality bar is met
When to Use
- Improving a skill with multiple quality issues
- Iterating on a new skill until it meets standards
- Automated fix-review cycles instead of manual editing
- Consistent quality enforcement across skills
When NOT to Use
- **One-time review**: Use `/skill-reviewer` directly instead
- **Quick single fixes**: Edit the file directly
- **Non-skill files**: Only works on SKILL.md files
- **Experimental skills**: Manual iteration gives more control during exploration
Issue Categorization
Critical Issues (MUST fix immediately)
These block skill loading or cause runtime failures:
- Missing required frontmatter fields (name, description) — Claude cannot index or trigger the skill
- Invalid YAML frontmatter syntax — Parsing fails, skill won't load
- Referenced files that don't exist — Runtime errors when Claude follows links
- Broken file paths — Same as above, leads to tool failures
Major Issues (MUST fix)
These significantly degrade skill effectiveness:
- Weak or vague trigger descriptions — Claude may not recognize when to use the skill
- Wrong writing voice (second person "you" instead of imperative) — Inconsistent with Claude's execution model
- SKILL.md exceeds 500 lines without using references/ — Overloads context, reduces comprehension
- Missing "When to Use" or "When NOT to Use" sections — Required by project quality standards
- Description doesn't specify when to trigger — Skill may never be selected
Minor Issues (Evaluate before fixing)
These are polish items that may or may not improve the skill:
- Subjective style preferences — Reviewer may have different taste than author
- Optional enhancements — May add complexity without proportional value
- "Nice to have" improvements — Consider cost-benefit before implementing
- Formatting suggestions — Often valid but low impact
Minor Issue Evaluation
Before implementing any minor issue fix, evaluate:
- **Is this a genuine improvement?** - Does it add real value or just satisfy a preference?
- **Could this be a false positive?** - Is the reviewer misunderstanding context?
- **Would this actually help Claude use the skill?** - Focus on functional improvements
Only implement minor fixes that are clearly beneficial. Skill-reviewer may produce false positives.
Invoking skill-reviewer
Use the skill-reviewer agent from the plugin-dev plugin. Request a review by asking Claude to:
> Review the skill at [SKILL_PATH] using the plugin-dev:skill-reviewer agent. Provide a detailed quality assessment with issues categorized by severity.
Replace `[SKILL_PATH]` with the absolute path to the skill directory (e.g., `/path/to/plugins/my-plugin/skills/my-skill`).
Example Fix Cycle
**Iteration 1 — skill-reviewer output:**
Critical: SKILL.md:1 - Missing required 'name' fi
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