How to use
- Copy the installation command and review the source package before installing it in your own agent environment.
- Check the source document for required tools, credentials and supported hosts.
- Describe your input and desired deliverable; review the output against the source material.
npx skills add https://github.com/callstackincubator/agent-skills --skill validate-skillsBefore you start
- Installation does not include a model subscription, API allowance or permission to access your files.
- Repository stars and installation counts describe activity, not an independent quality or security test.
Original skill document
Rendered from the source repository. Headings, examples, code, tables, links, and referenced images are preserved.
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, whereb.mdis not linked fromSKILL.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 fromSKILL.md. Only flag a reference that is reachable exclusively through another reference.
How to Run
- Find all skill directories:
bash
fd -t d -d 1 . skills/- For each skill, read
SKILL.mdand 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)
