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/ethansei/skills/claude-mdgit clone --depth 1 https://github.com/EthanSei/skillsWrote 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/ethansei/skills/claude-md)<a href="https://agentmods.dev/instructions/ethansei/skills/claude-md"><img src="https://agentmods.dev/badge/instructions/ethansei/skills/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 | $0.00535 | $0.00535 |
| Opus 5 | $0.00267 | $0.00267 |
| Sonnet 5 | $0.00107 | $0.00107 |
| Haiku 4.5 | $0.00053 | $0.00053 |
Grade A, and why
skills 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 50 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Project Conventions
This is a repository of agent skills following the Agent Skills specification.
Skill Structure
Each skill lives in skills/<skill-name>/ and must contain:
SKILL.md— YAML frontmatter (name,description) + markdown instructions- The
namefield must match the directory name (lowercase a-z, 0-9, hyphens; no leading/trailing/consecutive hyphens; max 64 chars) descriptionshould include trigger keywords so agents know when to activate the skill (max 1024 chars)- Keep
SKILL.mdunder 500 lines / ~5000 tokens; move detailed docs toreferences/
Optional frontmatter fields: license, compatibility, metadata (key-value map), allowed-tools
Optional directories:
scripts/— Python scripts using PEP 723 inline metadata for dependencies (run withuv run)references/— Additional documentation loaded on demandassets/— Static resources (templates, data files)
Skill Packs
Packs are named bundles of related skills defined in .claude-plugin/marketplace.json as entries in the plugins array. Each entry has:
name— Pack identifier (used for installation)description— What the pack providesskills— Array of paths to skill directories (e.g.,"./skills/my-skill")source— Always"./"strict— Set tofalseunless the pack should be the exclusive handler for matching tasks
A skill can belong to multiple packs. Users install a pack via /plugin install <pack-name>@ethansei-skills.
Python Scripts
- Use PEP 723 inline script metadata for dependency declarations
- Scripts must be non-interactive (no input prompts)
- Use structured output (JSON) over free-form text
- Include
--helpoutput - Support idempotency where possible
- Use meaningful exit codes
When Adding a New Skill
- Create
skills/<name>/SKILL.mdwith valid frontmatter - Consider adding the skill path to relevant packs in
.claude-plugin/marketplace.json - Update both tables in
README.md(Skill Packs and Available Skills)
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.
- 4d ago First seen · 50 lines · 535 tokens per session scan A b592b7be11e0
skills CLAUDE.md is an instructions file published in the GitHub repository EthanSei/skills (2 stars, last pushed 6mo ago), licensed MIT. It adds 535 tokens to every session, about $0.0027 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-release stance: foundation over blast radius, repository layout, commands and host sandbox failures.