What is a Claude Code Skill?

A Claude Code Skill is a specialized capability that enhances Claude's behavior by providing domain-specific guidance, best practices, and implementation patterns.

Why isn't my skill being invoked by Claude?

Common issues include vague descriptions or missing trigger keywords. This validator helps you audit your frontmatter to ensure Claude knows exactly when to use your skill.

Is there a recommended file size for skills?

Yes, SKILL.md files should ideally be under 500 lines. For larger skills, this tool recommends a directory structure with separate files for examples and reference material.

Does this skill help with cross-model compatibility?

Yes, it provides a testing workflow to ensure your skill works consistently across Claude Haiku, Sonnet, and Opus models.

Claude Skill Quality Validator

Name: Claude Skill Quality Validator
Author: edmundmiller

byedmundmiller

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Developer Tools

Validates and optimizes Claude Code skills against best practices for structure, discoverability, and content quality.

About

This skill provides a comprehensive framework for creating, reviewing, and debugging Claude Code skills. It ensures that specialized AI capabilities follow standardized structural patterns, include effective trigger keywords, and maintain high content quality. By using detailed checklists for metadata, file organization, and cross-model testing, users can build more reliable and effective custom behaviors for Claude, ensuring they are invoked correctly and provide actionable guidance.

Key Features

Content quality checklists with concrete example patterns
Cross-model testing protocols for Haiku, Sonnet, and Opus
42 GitHub stars
Standardized directory and file organization templates
Comprehensive debugging guides for skill invocation issues
Automated structure and YAML metadata validation

Use Cases

Refactoring large skill files into efficient directory-based structures
Auditing existing skills to improve invocation reliability and performance
Creating a new Claude Code skill from scratch with proper boilerplate

About

Key Features

Content quality checklists with concrete example patterns
Cross-model testing protocols for Haiku, Sonnet, and Opus
42 GitHub stars
Standardized directory and file organization templates
Comprehensive debugging guides for skill invocation issues
Automated structure and YAML metadata validation

Use Cases

Refactoring large skill files into efficient directory-based structures
Auditing existing skills to improve invocation reliability and performance
Creating a new Claude Code skill from scratch with proper boilerplate