What is SkillCheck used for?

SkillCheck is used to validate SKILL.md files against the agentskills specification to catch structural, semantic, and naming issues before they affect end-users.

What kind of issues does SkillCheck identify?

It identifies missing frontmatter fields, vague naming, logical contradictions in instructions, improper tool usage, and general content quality gaps.

How is the SkillCheck score calculated?

The tool uses a 0-100 scoring system where critical issues deduct 20 points, warnings deduct 5 points, and suggestions deduct 1 point.

Does this tool support security scanning?

The free version focuses on structural and naming checks; advanced features like security scanning, anti-slop detection, and token analysis require SkillCheck Pro.

Does SkillCheck modify my local files?

No, SkillCheck is a read-only tool. it parses and analyzes your SKILL.md content to provide a report but does not make any direct modifications to your files.

SkillCheck: Claude Skill Validator

Name: SkillCheck: Claude Skill Validator
Author: JantonioFC

byJantonioFC

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Developer Tools

Validates SKILL.md files against the agentskills specification to ensure structural integrity and high-quality AI agent behavior.

SkillCheck is a specialized diagnostic utility designed for developers building Claude Code skills, ensuring every SKILL.md file adheres to the agentskills specification and Anthropic best practices. By performing a comprehensive read-only analysis, it identifies structural errors, semantic contradictions, and naming anti-patterns that could prevent a skill from triggering or performing as intended. This tool provides an objective quality score and detailed reports with actionable fix suggestions, making it an essential part of the development workflow for anyone creating, debugging, or publishing AI capabilities.

Key Features

01Semantic contradiction and ambiguity detection

02Naming pattern and discoverability auditing

03Automated agentskills specification validation

042 GitHub stars

05Structural integrity checks for YAML frontmatter and XML injection

06Objective quality scoring (0-100) with detailed reporting

Use Cases

01Debugging trigger failures or inconsistent behavior in Claude Code

02Reviewing skills for quality and compliance before marketplace submission

03Onboarding development teams to standardized skill-authoring patterns

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add jantoniofc/skillsbank skill-check

For use in Claude.ai and ChatGPT