Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/woohyun212/security-skill/claude-mdgit clone --depth 1 https://github.com/woohyun212/security-skillWrote 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.
[](https://agentmods.dev/instructions/woohyun212/security-skill/claude-md)<a href="https://agentmods.dev/instructions/woohyun212/security-skill/claude-md"><img src="https://agentmods.dev/badge/instructions/woohyun212/security-skill/claude-md.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00403 | $0.00403 |
| Opus 5 | $0.00201 | $0.00201 |
| Sonnet 5 | $0.00081 | $0.00081 |
| Haiku 4.5 | $0.00040 | $0.00040 |
Grade A, and why
security-skill CLAUDE.md scanned grade A with 0 findings 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 5d 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
security-skill Development Rules
Project Overview
A collection of security skills for AI agents. Each skill is a markdown instruction file in the form <skill-name>/SKILL.md.
Skill Rules
- Skill directories are placed flat at the root (no nesting)
- Each skill directory contains
SKILL.mdand an optionalREFERENCE.md REFERENCE.mdholds lookup tables, templates, checklists, and other static reference dataSKILL.mdshould stay under 400 lines — extract heavy reference material toREFERENCE.md- The
name:frontmatter inSKILL.mdmust match the directory name exactly - Skills delegate execution to existing security tools (nmap, nuclei, subfinder, etc.)
- Skills must not contain executable source code
SKILL.md Frontmatter Required Fields
name: <directory-name>
description: <one-line English description>
license: MIT
metadata:
category: <recon|vuln-analysis|web-security|crypto|incident-response|compliance|code-security>
locale: ko-KR
phase: v1
Security Principles
- All skills cover only legitimate security testing/defensive purposes
- Skills must not contain attack automation code — provide tool usage instructions only
- Credentials for external APIs requiring authentication are managed via environment variables
- Credential resolution order: environment variables →
~/.config/security-skill/secrets.env→ query the user
Validation
./scripts/validate-skills.sh # Validate all skill structures
npm test # Documentation convention tests
Directory Structure
<skill-name>/SKILL.md— skill definition (workflow and instructions)<skill-name>/REFERENCE.md— optional reference data (tables, templates, checklists)scripts/— validation and utilitiesdocs/— documentationpackages/— future npm packages
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.
- 5d ago First seen · 44 lines · 403 tokens per session scan A d36e45ebc530
security-skill CLAUDE.md is an instructions file published in the GitHub repository woohyun212/security-skill (21 stars, last pushed 4mo ago), licensed MIT. It adds 403 tokens to every session, about $0.0020 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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