validate-skills

Validate Skills

Validate all skills in skills/ against the agentskills.io spec and Claude Code best practices.

Validation Checklist

For each skill directory, verify:

Spec Compliance (agentskills.io)

Check	Rule
name format	1-64 chars, lowercase alphanumeric + hyphens, no leading/trailing/consecutive hyphens
name matches directory	Directory name must equal name field
description length	1-1024 characters, non-empty
Optional fields valid	license, metadata, compatibility if present

Best Practices (Claude Code)

Check	Rule
Description format	Third person, describes what + when to use
Body length	Under 500 lines
Loading is one-level deep	SKILL.md is the only progressive-disclosure entry point: every reference file must be reachable from SKILL.md. References may cross-link each other for navigation (see note below).
Links are markdown	Use [text](https://raw.githubusercontent.com/callstackincubator/agent-skills/main/path) not bare filenames
No redundancy	Don't repeat description in body
Concise	Only add context Claude doesn't already have

One-level-deep vs. cross-linking. The one-level-deep rule targets progressive-disclosure loading chains — a reference that can only be discovered by loading another reference first (SKILL.md → a.md → b.md, where b.md is not linked from SKILL.md). That is a defect: it hides content from the loader.

It does not forbid navigational cross-links. Per AGENTS.md, reference files end with a "Related Skills" footer linking sibling references, and this is required. A cross-link is fine as long as both endpoints are also reachable directly from SKILL.md. Only flag a reference that is reachable exclusively through another reference.

How to Run

1. Find all skill directories:

   fd -t d -d 1 . skills/
   

2. For each skill, read SKILL.md and check against the rules above

3. Report issues in this format:

   ## Validation Results
   
   ### skills/example-skill
   - [PASS] name format valid
   - [FAIL] name "example" doesn't match directory "example-skill"
   - [PASS] description length OK (156 chars)
   

References

• agentskills.io spec
• Claude Code best practices