Skill Reviewer

Skill Reviewer

Review existing skills and generate actionable improvement suggestions using both inline patch/diff format and structured JSON output.

When to Use

• User explicitly requests review of a skill at a specific path
• User is drafting or creating a new skill (auto-trigger)
• After running uvx skills-ref validate to understand spec violations

Core Workflow

1. Load & Parse

Identify the skill path to review:

• Explicit: User provides skill path directly
• Auto-trigger: User mentions "new skill", "create skill", "draft skill" → review the SKILL.md being created

Read the target skill's SKILL.md:

• Extract YAML frontmatter (name, description, optional fields)
• Parse body content for structural analysis

2. Validate with skills-ref

Run the Agent Skills validation CLI:

uvx skills-ref validate ./path/to/skill

This catches:

• Invalid frontmatter YAML syntax
• Missing required fields (name, description)
• Name format violations (must be hyphen-case, max 64 chars)
• Description over 1024 characters
• Unexpected frontmatter fields

3. Review Against Criteria

Evaluate the skill using the criteria in references/review-criteria.md:

Frontmatter Checks

• name field present and valid (hyphen-case, ≤64 chars)
• description field present (≤1024 chars, no angle brackets)
• No unexpected fields (only: name, description, license, metadata, compatibility, allowed-tools)

Description Quality

• Imperative phrasing ("Use when..." not "This skill does...")
• Focus on user intent, not implementation
• Specific keywords for triggering
• Clear when-to-use scenarios

Body Structure

• Concise instructions (<500 lines preferred)
• Progressive disclosure (main points in SKILL.md, details in references/)
• No agent-specific references ("Claude", "Gemini", etc.)
• Examples where helpful

Resource Organization

• Scripts in scripts/ if needed
• Reference docs in references/ if needed
• Assets in assets/ if needed

4. Generate Improvements

Produce two output formats:

Inline Patch/Diff

Use filepath comments for "Apply to file" functionality:

// filepath: skill/SKILL.md
// ...existing code...

```yaml
---
name: my-skill
description: Use when working with CSV files for analysis and visualization.
---
```

// ...existing code...

Structured JSON

For programmatic consumption:

{
  "skill_path": "/path/to/skill",
  "issues": [
    {
      "severity": "critical",
      "file": "SKILL.md",
      "line": 1,
      "text": "Missing required 'name' field in frontmatter",
      "fix": "Add `name: my-skill` to frontmatter"
    },
    {
      "severity": "major",
      "file": "SKILL.md",
      "line": 3,
      "text": "Description uses second person ('you should use') instead of imperative",
      "fix": "Rewrite as 'Use when...' imperative phrasing"
    }
  ],
  "summary": {
    "critical": 1,
    "major": 2,
    "minor": 0
  }
}

5. Issue Categorization

Group issues by severity (from skill-improver methodology):

Critical — MUST fix immediately

• Missing required frontmatter fields (name, description)
• Invalid YAML syntax
• Referenced files that don't exist

Major — MUST fix

• Weak or vague trigger descriptions
• Wrong voice (second person instead of imperative)
• SKILL.md exceeds 500 lines without using references/
• Missing "When to Use" section
• Description doesn't specify when to trigger

Minor — Evaluate before fixing

• Subjective style preferences
• Optional enhancements
• Formatting suggestions

6. Iterate (Improver Loop)

For skill improvement workflows:

1. Present issues with inline patches
2. User applies fixes
3. Re-validate with uvx skills-ref validate
4. Re-review remaining issues
5. Continue until no critical/major issues remain

Output completion marker when done:

<skill-review-complete>

Resources

• Review Criteria — Detailed evaluation checklist
• Improvement Patterns — Common issues and fixes
• quick_review.py — Lightweight validation script