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/callstackincubator/agent-skills/agents-mdgit clone --depth 1 https://github.com/callstackincubator/agent-skillsWhat 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 | $0.00709 | $0.00709 |
| Opus 5 | $0.00354 | $0.00354 |
| 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 3d 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 — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Skills
Markdown-only repo with agent skills for React Native and GitHub workflows. No build step.
Adding New Skills
Follow agentskills.io spec and Claude Code best practices.
Quick Checklist
- Create
skills/<skill-name>/SKILL.md - Directory name must match
namefield exactly - Required frontmatter:
--- name: skill-name # lowercase, hyphens only, 1-64 chars description: Third person description of what it does. Use when [trigger conditions]. --- - Optional frontmatter:
license,metadata(author, tags),compatibility - Keep body under 500 lines
- Use markdown links:
[file.md](references/file.md)not bare filenames - Run
/validate-skillsto verify
What Makes a Good Skill
- Concise: Only add context Claude doesn't already have
- Third person description: "Processes X" not "I help with X"
- What + When: Description says what it does AND when to use it
- One-level deep: Reference files link from SKILL.md, not from other references
- No redundancy: Don't repeat description content in body
Repo Structure
skills/
├── react-native-best-practices/
│ ├── SKILL.md # Main entry point with quick reference + problem→skill mapping
│ └── references/
│ ├── images/ # Visual references (profiler screenshots, diagrams)
│ ├── js-*.md # JavaScript/React skills
│ ├── native-*.md # iOS/Android native skills
│ └── bundle-*.md # Bundling & app size skills
│
└── react-native-tv-best-practices/
├── SKILL.md # Main entry point with priority framework + problem→reference routing
└── references/
├── focus-*.md # Focus / D-pad navigation
├── nav-*.md # Directional navigation & keyboard
├── design-*.md # 10-foot design (typography, layout, color)
├── perf-*.md # TV performance (lists, memory, animations)
├── video-*.md # Video streaming, players, DRM
├── a11y-*.md # TV accessibility
├── setup-*.md # Cross-platform setup & architecture
├── test-*.md # Testing strategy
└── release-*.md # CI/CD
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.
- 3d ago First seen · 72 lines · 709 tokens per session scan A 8995509d82f1
agent-skills AGENTS.md is an instructions file published in the GitHub repository callstackincubator/agent-skills (1,633 stars, last pushed 25d ago), licensed MIT. It adds 709 tokens to every session, about $0.0035 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.
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.