/ Directory / Playground / SkillCheck-Free
← All servers ↗ GitHub
● Community olgasafonova ⚡ Instant

SkillCheck-Free

by olgasafonova · olgasafonova/SkillCheck-Free

Validates Claude Code skills against the open agentskills spec — structure, body, naming, semantics, quality patterns — Critical / Warning / Suggestion.

olgasafonova/SkillCheck-Free is a spec-compliance linter for Agent Skills. Free tier covers: 1.x Structure (YAML frontmatter, name validity, description quality, XML injection), 2.x Body (length, hardcoded dates, empty sections, unqualified MCP refs), 3.x Naming (generic names, verb-noun), 4.x Semantic (conflicting instructions, vague terms, unspecified outputs), 8.x Quality patterns (examples, error handling, triggers), 19.x Design pattern classification, 22.x Knowledge density. Severity tiers: Critical / Warning / Suggestion / Strength.

▶ Watch demo 📦 Install 💡 Use Cases

Why use it

Key features

Live Demo

What it looks like in practice

skillcheck-free-skill.replay ▶ ready
0/0

Install

Author repository · Claude Skills documentation

Use Cases

Real-world ways to use SkillCheck-Free

Validate your skill before publishing it to a catalog

👤 Skill authors ⏱ ~20 min beginner

When to use: Before opening a PR to awesome-claude-skills or anthropics/skills.

Flow
  1. Run SkillCheck on your SKILL.md
    Use SkillCheck-Free — validate ~/my-skill/SKILL.md against the agentskills spec.✓ Copied
    → Per-rule findings with severities
  2. Fix Critical issues
    Walk me through each Critical finding and propose a fix.✓ Copied
    → Concrete edits, not 'improve clarity'
  3. Re-run until clean
    Re-validate. Anything still Critical or Warning?✓ Copied
    → Progress toward zero Critical

Outcome: A skill that won't be rejected for trivial spec violations.

Pitfalls
  • Chasing every Suggestion — Suggestions are aspirational; Critical + Warning is the bar for most catalogs
Combine with: skills-skill-8 · awesome-claude-skill-2

Audit every skill you've installed for quality concerns

👤 Skill hoarders who want to prune ⏱ ~30 min intermediate

When to use: You installed 20 skills and aren't sure which ones are well-made.

Flow
  1. Decide what to keep
    Which skills have persistent Critical issues I should uninstall?✓ Copied
    → Prioritized uninstall candidates

Outcome: A leaner, higher-quality skill collection.

Combinations

Pair with other MCPs for X10 leverage

skillcheck-free-skill + skills-skill-8

Cross-check: SkillCheck validates spec, huangwb8/auto-test-skill tests robustness

Run SkillCheck first for spec issues, then auto-test-skill for design weaknesses.✓ Copied
skillcheck-free-skill + awesome-claude-skill-2

Validate before submitting your skill to the catalog

SkillCheck my SKILL.md, then if clean, draft the awesome-claude-skills PR.✓ Copied

Tools

What this MCP exposes

ToolInputsWhen to callCost
validate_skill path to SKILL.md Pre-publish or post-install 0
classify_pattern skill body Understanding how a skill fits your collection 0
batch_validate directory of skills Fleet-wide audit 0

Cost & Limits

What this costs to run

API quota
None
Tokens per call
Small — typical SKILL.md is <10k tokens
Monetary
Free tier only; Pro tier exists for deeper pattern validation
Tip
Free tier is sufficient for most authoring — upgrade only if you publish commercially.

Security

Permissions, secrets, blast radius

Credential storage: No credentials — pure prompts
Data egress: None — validation is local

Troubleshooting

Common errors and fixes

SKILL.md frontmatter wrong in target skill

Expected — that's the finding SkillCheck exists to surface. Fix the frontmatter and re-run.

Verify: head <target>/SKILL.md
Wrong trigger keywords — SkillCheck runs but misses severity tier

Ask explicitly for 'severity-tiered output'; default may compress.

Alternatives

SkillCheck-Free vs others

AlternativeWhen to use it insteadTradeoff
skills-skill-8 auto-test-skillYou want design robustness testing, not spec complianceComplementary — run both
Manual reviewYou've written many skills and have internalized the specNo machine backstop for subtle issues

More

Resources

📖 Read the official README on GitHub

🐙 Browse open issues

🔍 Browse all 400+ MCP servers and Skills

Continue exploring

Related tools and workflows

Choose another guide for your workflow, or explore a collection.

Browse all topic collections → · See 29 new official additions →