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validate-skills

Validates skills in this repo against agentskills.io spec and Claude Code best practices.

Skill by Callstack

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Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/callstackincubator-validate-skills

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

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About

Validates skills in this repo against agentskills.io spec and Claude Code best practices. Use via /validate-skills command.

Use cases: agent-building

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Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
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Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/validate-skills

What's inside

Skill name
validate-skills
Description
Validates skills in this repo against agentskills.io spec and Claude Code best practices. Use via /validate-skills command.
License
MIT
Metadata
tags: validation, linting, skill-authoring · author: Callstack
Instructions
57 lines in SKILL.md · view on GitHub

Files (1)

  • SKILL.md

SKILL.md (first lines)

# 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](../../../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:
   ```bash
   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](https://agentskills.io/specification)
- [Claude Code best practices](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/best-practices)

From callstackincubator/agent-skills, MIT.

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Last commit (this folder)
Jun 30, 2026 (3 months ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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Cite this page

validate-skills. Agent Mart. https://agentmart.dev/skills/callstackincubator-validate-skills (last updated 2026-10-24)