validate-skills

SKILL.md

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](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

Find all skill directories:

fd -t d -d 1 . skills/

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

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

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