agentic-tools AGENTS.md

Repository guidance for AI coding agents working on a collection of workflow skills for Meta's developer platform. It explains the repository layout, its plugin marketplaces, and the Developer Tools MCP server.

In plain words
What is it for?
Use it when developing skills or plugins for Meta developer tools, including app management, webhooks, compliance checks, app review, API monitoring, and documentation search.
Why use it?
It helps an agent find the right plugin files and follow the repository's organization when changing or adding skills.

Instructions file for CodexOpenCode

Install

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.

agentmods
npx agentmods add instructions/facebook/agentic-tools/agents-md
Clone the repo
git clone --depth 1 https://github.com/facebook/agentic-tools

Made for: Codex, OpenCode.

Per session 1,584 This file is loaded in full into every session.
When invoked 1,584 The same file — it is already loaded in full.
Security scan B 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.01584 $0.01584
Opus 5 $0.00792 $0.00792
Sonnet 5 $0.00317 $0.00317
Haiku 4.5 $0.00158 $0.00158

Measured yesterday against content hash 2ce37fb90f2d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

agentic-tools AGENTS.md scanned grade B with 1 finding 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 yesterday.

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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

- **Codex**: install via `$skill-installer`, and add the MCP to `~/.codex/config.toml` (see README).
AGENTS.md · 94 lines

How it starts

The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Guide — Agentic Tools

This file helps AI agents navigate and use this repository effectively.

What this repo is

A skills repository for AI coding agents that provides workflow-oriented guidance for the Meta Developer Platform. Skills wrap the Developer Tools MCP server tools into higher-level workflows for app management, webhook configuration, compliance auditing, app review preparation, API health monitoring, and documentation search.

How this repo is organized

This repo is a multi-plugin marketplace. Two marketplace manifests live at the repo root — .claude-plugin/marketplace.json (Claude Code / Codex) and .cursor-plugin/marketplace.json (Cursor) — and each product group is a self-contained plugin under plugins/<group>/. Today there is one group, the Developer Tools plugin (devtools). To add another product group later, drop in a sibling plugins/<group>/ and add an entry to both marketplace manifests — no restructuring.

Each plugin (plugins/devtools/) contains:

  • .claude-plugin/plugin.json — Claude Code plugin manifest
  • .cursor-plugin/plugin.json — Cursor plugin manifest
  • .codex-plugin/plugin.json — Codex plugin manifest
  • .mcp.json — MCP server config for Claude Code / Codex (auto-bundled with the plugin)
  • mcp.json — MCP server config for Cursor (auto-discovered at the plugin root)
  • skills/<name>/SKILL.md — the skills
  • hooks/ — session hooks

Skills follow the open Agent Skills standard (SKILL.md), which Claude Code, Cursor, and Codex all understand. Agents should read SKILL.md for the skill invoked by the user. Each skill declares its allowed-tools in the frontmatter (used by Claude to scope MCP tool access; ignored harmlessly by other agents).

MCP server dependency

All skills require the Developer Tools MCP server to be connected. This is a remote streamable-HTTP server (https://mcp.facebook.com/devtools). There is no standalone CLI — the skills drive the MCP for all their work, so it must be connected first.

Read the full file on GitHub · 94 lines

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.

  1. yesterday First seen · 94 lines · 1,584 tokens per session scan B 2ce37fb90f2d

Subscribe to this mod's changes

agentic-tools AGENTS.md is an instructions file published in the GitHub repository facebook/agentic-tools (5 stars, last pushed 11d ago), licensed MIT. It adds 1,584 tokens to every session, about $0.0079 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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