Skill Linter & Advisor#

Analyze SKILL.md files against Claude Code Skills best practices and provide actionable feedback.

Analysis Process#

1. Read the SKILL.md file - Load the complete content
2. Parse frontmatter - Validate YAML structure and required fields
3. Check content structure - Verify best practices for the markdown body
4. Compare against patterns - Match against known good Skill patterns
5. Generate report - Provide structured feedback with severity levels

Validation Checklist#

Frontmatter (YAML Header)#

CheckSeverityDescriptionHas --- delimiters🔴 CriticalMust have opening and closing ---Valid YAML syntax🔴 CriticalYAML must parse without errorsHas name field🟡 WarningDefaults to directory name, but explicit is betterHas description🔴 CriticalRequired for auto-trigger to workDescription quality🟡 WarningShould be specific, mention when to usedisable-model-invocation🟢 InfoOnly set if you want manual-onlyuser-invocable🟢 InfoSet to false to hide from / menuallowed-tools🟡 WarningSpecify if Skill needs specific toolsmodel override🟢 InfoOnly if you need specific modelcontext: fork🟢 InfoUse for long-running or isolated tasksagent with context🟢 InfoRequired when context: fork

Content Structure#

CheckSeverityDescriptionHas clear title/heading🟡 WarningFirst line should indicate purposeHas process/steps🟡 WarningSkills should have actionable stepsHas output format🟡 WarningDefine expected output structureUses specific language🟡 WarningAvoid vague terms like "etc", "etc."Has examples🟢 InfoConcrete examples improve reliabilityHas constraints/guardrails🟢 InfoDefine what NOT to doAppropriate length🟡 WarningToo short (<100 words) or too long (>2000)

Common Issues#

IssueSeverityFixMissing description🔴 CriticalAdd description explaining when to triggerDescription too vague🟡 WarningBe specific about use casesNo clear output format🟡 WarningAdd expected output structureMissing tool declarations🟡 WarningAdd allowed-tools if using toolsToo many responsibilities🟡 WarningSplit into multiple focused SkillsHardcoded paths🟡 WarningUse variables or relative pathsNo error handling guidance🟢 InfoAdd what to do when things go wrong

Output Format#

text

# Skill Analysis Report

## File: {filepath}

### Frontmatter Analysis

| Field | Status | Value | Notes |
|-------|--------|-------|-------|
| name | ✅/⚠️/❌ | {value} | {feedback} |
| description | ✅/⚠️/❌ | {value} | {feedback} |
| ... | | | |

**Frontmatter Score:** X/10

### Content Analysis

| Check | Status | Notes |
|-------|--------|-------|
| Has clear purpose | ✅/⚠️/❌ | {feedback} |
| Actionable steps | ✅/⚠️/❌ | {feedback} |
| Output format defined | ✅/⚠️/❌ | {feedback} |
| Has examples | ✅/⚠️/❌ | {feedback} |
| Appropriate length | ✅/⚠️/❌ | {word_count} words |

**Content Score:** X/10

### Issues Found

#### 🔴 Critical (Must Fix)
1. {issue description} → {fix suggestion}

#### 🟡 Warnings (Should Fix)
1. {issue description} → {fix suggestion}

#### 🟢 Suggestions (Nice to Have)
1. {issue description} → {fix suggestion}

### Overall Assessment

**Total Score:** X/10

**Verdict:**
- ✅ Excellent - Ready to use
- 🟡 Good - Minor improvements suggested
- ⚠️ Needs Work - Address warnings before using
- ❌ Critical Issues - Must fix before using

### Recommended Actions

1. {action item}
2. {action item}
3. {action item}

### Improved Version (Optional)

If significant improvements are needed, provide a rewritten SKILL.md:

```yaml
---
# improved frontmatter
---

# Improved content...

text

## Skill Patterns Reference

### Pattern 1: Checklist/Task Skill
For: Code review, testing, validation tasks

Structure:
- Clear trigger description
- Step-by-step process
- Checklist categories
- Severity ratings
- Structured output format

### Pattern 2: Generator Skill
For: Documentation, commit messages, reports

Structure:
- Input requirements
- Analysis steps
- Template/format specification
- Examples
- Constraints

### Pattern 3: Explorer/Research Skill
For: Code exploration, debugging, analysis

Structure:
- Context gathering (!commands)
- Investigation steps
- What to look for
- How to present findings

### Pattern 4: Workflow Skill
For: Multi-step processes, releases, deployments

Structure:
- Prerequisites check
- Sequential steps
- Validation points
- Rollback guidance

## Examples of Good Descriptions

✅ **Good:**
- "Perform a thorough code review following the team checklist. Use when reviewing code changes, pull requests, or when the user asks for a code review."
- "Generate API documentation from source code. Use when the user asks to document an API endpoint, route handler, or controller."
- "Create a standardized git commit message following Conventional Commits format. Use when the user asks to commit or create a commit message."

❌ **Bad:**
- "Does code review" (too vague)
- "Helps with documentation" (when?)
- "A skill for git" (too broad)

## Examples of Good Output Formats

✅ **Good:**
```markdown
## Output Format

Structure your review as:

**Summary**
[One-paragraph overall assessment]

**Critical Issues**
[Must fix before merging]

**Approved?**
[YES / NO / YES WITH CONDITIONS]

❌ Bad:

markdown

Just give me a review of the code.