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/coroboros/agent-skills/agents-mdgit clone --depth 1 https://github.com/coroboros/agent-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/coroboros/agent-skills/agents-md)<a href="https://agentmods.dev/instructions/coroboros/agent-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/coroboros/agent-skills/agents-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 | $0.00710 | $0.00710 |
| Opus 5 | $0.00355 | $0.00355 |
| Sonnet 5 | $0.00142 | $0.00142 |
| Haiku 4.5 | $0.00071 | $0.00071 |
Grade A, and why
agent-skills AGENTS.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 — 34 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Skills
Rule Index
Project-level behavior guidance indexed from .agents/rules/.
Before planning or editing, read this rule first:
.agents/rules/behavior.md- canonical behavior discipline: production-grade, size budget, surgical, fail-loud, never-invent..agents/rules/behavior-frontier.md- Frontier addendum — model scope stated in the file.
Public collection of installable AI agent skills for Claude Code and compatible agents. Each skill is a self-contained folder in skills/ with a SKILL.md at its root.
Repo rules
.agents/rules/agentskills-spec.md— canonical frontmatter, folder anatomy, size budget.agents/rules/claude-code-skills.md— Claude Code extensions and string substitutions.agents/rules/skill-authoring.md— mandatoryskill-creatorflow + the testing requirement.agents/rules/repo-conventions.md— flags, output paths, install, plugin marketplace, test placement.agents/rules/skill-{prose,label-hygiene,execution-discipline,adversarial-verification}-rules.md— canonical blocks synced into declaring SKILL.md bodies byscripts/sync_writing_rules.py
At a glance
- Standard: agentskills.io open standard (frontmatter, folder anatomy) + Claude Code extensions for Claude Code-scoped skills.
- Authoring tool: the official Anthropic
skill-creatorskill is mandatory for creating/updating skills. We do not build our own. - Layout:
skills/{name}/SKILL.md+ optionalsteps/,templates/,scripts/,references/. No per-skillREADME.md. - Install:
npx skills add coroboros/agent-skills --skill <name>via skills.sh. - Runtime: bash + Python 3 (stdlib only) for bundled scripts. Skills never resolve their own analyzer, converter, or helper packages while they run. Operations backed by external CLIs declare those prerequisites in their SKILL.md and fail with exact install plus rerun guidance when an applicable CLI is unavailable. A skill whose explicit purpose is project or package creation may install the project dependencies the user requested; the org-wide Bun preference does not apply to these portable scripts.
- Git — branch
main; noCHANGELOG.md(release notes live in thegh release createbody only); version lives only in git tags and in.claude-plugin/marketplace.jsonmetadata.version— there is nopackage.json, so nopnpm versionbump. All other rules in~/.agents/rules/git-conventions.mdapply. - Security —
cisco-ai-defense/skill-scannerscans theskills/tree on every push and PR via.github/workflows/scan-skills.yml(policybalanced, fail-oncritical). SHA-pinned to a tagged release; Dependabot auto-PRs new versions weekly. - Validation —
python3 -m unittest discover tests/before reporting done;scripts/sync_writing_rules.pyafter editing a canonicalskill-*-rules.mdblock.
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 · 34 lines · 710 tokens per session scan A c5a6915fc421
agent-skills AGENTS.md is an instructions file published in the GitHub repository coroboros/agent-skills (4 stars, last pushed 2d ago), licensed MIT. It adds 710 tokens to every session, about $0.0036 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.
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.
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).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.