skills-check: Instructions file for Claude Code

CLAUDE.md

skills-check CLAUDE.md is an instructions file for Claude Code from voodootikigod/skills-check. It costs 6,397 tokens per session, scanned C, original, MIT.

Repository instructions for skills-check, a quality and safety checker for Agent Skills. Agent Skills are instruction files that guide coding agents, so this project checks whether those files are correct, safe, current, and efficient.

In plain words
What is it for?
Use them when changing skill analysis, verification, maintenance, security checks, or the reusable GitHub Action.
Why use it?
They clarify the project's boundaries and prevent it from duplicating the separate tool that installs and distributes skills.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code; mentions Codex.

This is voodootikigod/skills-check's own configuration. It tells Claude Code how to work on skills-check itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything skills-check configures →

Reuse

Borrowing it

Nothing to install: this file belongs to voodootikigod/skills-check. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/voodootikigod/skills-check/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/voodootikigod/skills-check

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for skills-check CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/voodootikigod/skills-check/claude-md/github.svg)](https://agentmods.dev/instructions/voodootikigod/skills-check/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/voodootikigod/skills-check/claude-md"><img src="https://agentmods.dev/badge/instructions/voodootikigod/skills-check/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for skills-check CLAUDE.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/voodootikigod/skills-check/claude-md"><img src="https://agentmods.dev/badge/instructions/voodootikigod/skills-check/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 6,397 This file is loaded in full into every session.
When invoked 6,397 The same file — it is already loaded in full.
Security scan C 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.06397 $0.06397
Opus 5 $0.03198 $0.03198
Sonnet 5 $0.01279 $0.01279
Haiku 4.5 $0.00640 $0.00640

Measured 10d ago against content hash 0bb3f5264f88, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade C, and why

skills-check CLAUDE.md scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Hidden instructionshighPrompt injection

Directives inside HTML comments, invisible characters or bidirectional overrides are read by the model and not by the person reviewing the file.

ignore.ts # .skills-checkignore parsing + inline <!-- audit-ignore --> support
CLAUDE.md · 343 lines

How it starts

The opening of the file, as written. The whole thing — 343 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

What This Project Is

skills-check is the quality and integrity layer for Agent Skills. It answers: "Are my skills correct, safe, current, and efficient?"

Agent Skills are SKILL.md files — markdown documents with YAML frontmatter that instruct AI coding agents (Claude Code, Cursor, Codex, etc.) how to work with specific products, frameworks, and patterns. Skills look like documentation but are treated as executable instructions by agents with file system and shell access. This makes skill quality a security and correctness concern, not just a readability one.

skills-check sits alongside skills.sh (which handles installation, discovery, and distribution) as the complementary verification layer. skills.sh installs them, skills-check keeps them safe. The skills.sh maintainer is a colleague — skills-check should leverage and complement skills.sh, never duplicate or compete with it. The repo also doubles as a reusable GitHub Action (voodootikigod/skills-check@v1).

Scope: What skills-check owns

skills-check focuses on analyzing, verifying, and maintaining skills — not distributing them. Capabilities that belong here answer questions like:

  • Is this skill current? — Version drift detection, staleness checking (check, refresh)
  • Is this skill safe? — Security audit, hallucination detection, prompt injection scanning (audit)
  • Is this skill well-formed? — Metadata validation, structural linting (lint)
  • Is this skill efficient? — Context window token cost analysis (budget)
  • Is this skill's version bump honest? — Content-change-to-version-bump verification (verify)
  • Does this skill still work? — Eval/test integration for regression detection (test)
  • Does this skill comply with our policies? — Organizational trust rules and enforcement (policy)

Scope: What skills-check does NOT own

Read the full file on GitHub · 343 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 343 lines · 6,397 tokens per session scan C 0bb3f5264f88

Subscribe to this mod's changes

skills-check CLAUDE.md is an instructions file published in the GitHub repository voodootikigod/skills-check (13 stars, last pushed 1mo ago), licensed MIT. It adds 6,397 tokens to every session, about $0.0320 per session on Opus 5. A static security scan graded it C with 1 finding (hidden instructions). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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