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/ethandm/youtube-mcp/agents-mdgit clone --depth 1 https://github.com/EthanDM/youtube-mcpWrote 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/ethandm/youtube-mcp/agents-md)<a href="https://agentmods.dev/instructions/ethandm/youtube-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/ethandm/youtube-mcp/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 5.1 | $0.00560 | $0.00560 |
| Opus 5 | $0.00280 | $0.00280 |
| Sonnet 5 | $0.00112 | $0.00112 |
| Haiku 4.5 | $0.00056 | $0.00056 |
Grade A, and why
youtube-mcp 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 — 38 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Purpose
This repository is a local YouTube MCP for public discovery, bounded comment retrieval, local caption-track research, and explicitly scoped owned-playlist management. It is published as source code, but each installation uses its own local credentials and OAuth session.
Working Rules
- Keep the tool surface small and workflow-oriented.
- Do not add account-library tools, media downloads, ASR/Whisper fallback, caching, persistence beyond the local OAuth token store, or write actions outside owned-playlist management without an explicit product decision.
- Keep API-key public reads in the centralized GET-only request client. Keep OAuth-authenticated playlist reads and writes in the separate authenticated request client.
- Keep
yt-dlpcaption extraction local, explicit, read-only, and separate from the Data API client. Never use it to download media or persist transcript data. - Do not add transcript export, caching, or artifact persistence to the MCP. If an external assistant creates a user-requested transcript export, keep it outside the repository under
~/.config/youtube-mcp/artifacts/as user-local output, not server state. - Keep OAuth interactive and local through the auth CLI. Store tokens only in the private user-scoped token file; never expose them through MCP tools or Git.
- Authenticate playlist writes with OAuth and reject playlists not owned by the resolved authenticated channel. Require
confirm: truefor removal and reordering. - Verify every playlist mutation through an observed-state readback before reporting success. Cleanup planning is deterministic and read-only; do not infer subjective sequencing.
- Batch cleanup executes only explicit, confirm-gated planner removals after preflight; stop and report exact partial state on a write failure. Playlist cloning stays caller-bounded (five pages maximum), preserves source order, and never rolls back a partial target.
- Batch video adds are append-only, preflight every requested public video before the first write, and retain exact completed, remaining, and indeterminate IDs. Batch ordering requires a complete reviewed item-ID order for an owned playlist of at most 250 items; reject stale/incomplete orders before mutation and read back the final order.
- Keep transcript search bounded to the requested cursor window and state its retrieved-segments-only scope.
- Preserve explicit pagination. Never crawl comment pages implicitly.
- State the retrieved-page-only limit whenever local comment-term matching is used.
- Keep API keys and tunnel credentials outside Git.
- Prefer the built stdio server for normal use. Rebuild after source 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.
- 4d ago First seen · 38 lines · 560 tokens per session scan A a2aabc8f6880
youtube-mcp AGENTS.md is an instructions file published in the GitHub repository EthanDM/youtube-mcp (0 stars, last pushed 9d ago), licensed MIT. It adds 560 tokens to every session, about $0.0028 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
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 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.
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
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).