Agent Check

majiayu000/agent-check

Validate custom agent file format and structure

1k tokens

context cost

the whole folder, loaded on every use

files

instructions only

copies elsewhere

how many repositories repackaged it

532

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/majiayu000/claude-skill-registry --skill agent-check

What comes with it

830 bytes besides the instruction

metadata.json

What it tells the agent to use

found in the instruction text

WebFetch fetches pages from the network

WebSearch reads your files

The instruction itself

13 sections, as written by the author

Agent File Validator

Validate agent files in .claude/agents/ for correct format.

Validation Target

With argument: validate specific file
Without: validate all .claude/agents/*.md

Required Frontmatter

---
name: agent-name          # Required: lowercase, hyphenated, 3-50 chars
description: >            # Required: 10-5000 chars, include triggering conditions + <example> blocks
  Use this agent when [conditions]. Examples:
  <example>
  Context: [situation]
  user: "[request]"
  assistant: "[response using this agent]"
  </example>
color: cyan               # Required: yellow, red, green, blue, magenta, cyan
model: sonnet             # Required: inherit, haiku, sonnet, opus, best, sonnet[1m], opus[1m], opusplan
tools:                    # Optional: YAML list (omit = all tools available)
  - Read
  - Write
  - Grep
# forkContext: "true"     # Optional: run in forked context (string "true"/"false")
# maxTurns: 20            # Optional: max conversation turns (positive integer)
skills:                    # Optional: auto-load skills (array)
  - linked-skill
memory:                    # Optional: memory scopes to load (array)
  - user
  - project
  - local
mcpServers:                # Optional: MCP server refs or objects (array)
  - server-name
hooks:                     # Optional: agent-scoped lifecycle hooks
  PreToolUse:
    - matcher: Write
      hooks:
        - type: command
          command: ./validate.sh
  PostToolUse:
    - matcher: Bash
      hooks:
        - type: command
          command: ./log.sh
permissionMode: default    # Optional: permission handling
disallowedTools:           # Optional: explicit tool blocking
  - NotebookEdit
---

Valid Tools

Read, Write, Edit, Bash, Grep, Glob, Task,
WebFetch, WebSearch, TodoWrite, NotebookEdit

Valid Colors

yellow, red, green, blue, magenta, cyan

Valid Models

inherit, haiku, sonnet, opus, best, sonnet[1m], opus[1m], opusplan

Validation Checklist

Required Fields

[ ] name exists (lowercase, hyphenated, 3-50 chars)
[ ] description exists (10-5000 chars, recommend 200-1000 with <example> blocks)
[ ] color is set (valid color name)
[ ] model is set (inherit/haiku/sonnet/opus/best/sonnet[1m]/opus[1m]/opusplan)

Optional Fields

[ ] tools are valid tool names, YAML list format (omit = all tools available)
[ ] skills references existing skills (array, if set)
[ ] forkContext is string "true" or "false" (if set)
[ ] maxTurns is positive integer (if set)
[ ] memory is valid array of: user, project, local (if set)
[ ] mcpServers is valid array of string refs or objects (if set)
[ ] hooks has valid structure (if set)
[ ] permissionMode is valid value (if set)
[ ] disallowedTools are valid tool names (if set)

Content Structure

[ ] # Agent Name heading
[ ] ## Activation section
[ ] Process/workflow description
[ ] Output format definition

Format Rules

[ ] tools uses YAML list format (not [Read, Write] bracket array)
[ ] No duplicate tools in list
[ ] All tools are valid tool names

Output Format

## Agent Validation Report

### Files Checked
| File | Status | Issues |
|------|--------|--------|
| code-reviewer.md | OK | None |
| my-agent.md | WARN | Missing color, model |

### Summary
- Total: [N]
- Valid: [N]
- Needs fixes: [N]

Auto-Fix

Convert bracket array tools to YAML list format
Convert string skills to YAML array
Add missing color field (default: cyan)
Add missing model field (default: inherit)
Convert boolean forkContext to string
Convert scalar memory to array format
Remove invalid tools
Add recommended sections

How to use it

Copy the folder

Take majiayu000/agent-check from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.