mcptoon git:20260908.2c50386A

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name: mcptoon
description: Compress MCP tool discovery with the mcptoon CLI. Trigger when a session has a large MCP tool catalog (many servers/tools), when the user mentions token cost, tool discovery, mcptoon, or asks to list/call MCP tools efficiently. mcptoon compresses 71,929 tokens of tool schemas to 581 (-99.2%) and serves as an MCP 2026-07-28 stateless-first bridge.
---

# mcptoon — MCP tool-catalog compression

mcptoon is a zero-dependency CLI. If it is not installed yet, one command sets
it up: `pip install mcptoon` (128KB, installs in seconds, nothing else pulled
in). It gives you a compressed view of the user's MCP tools and calls them
back.

## When to use what

| Situation | Command |
|---|---|
| User asks "what tools do I have" / you need the tool catalog | `mcptoon manifest` (compact names only — ~2.2 tokens/tool) |
| You need one tool's real parameter schema before calling | `mcptoon inspect <server> <tool>` |
| Find a tool by capability | `mcptoon search <query>` |
| Call a tool | `mcptoon call <server> <tool> '{"arg":"value"}'` |
| You don't know which server owns the tool | `mcptoon call --auto <tool> '{...}'` |
| Huge JSON argument | `mcptoon call <server> <tool> --stdin` |
| Tool returns images/base64 that must never be compressed | `mcptoon policy set <server> <tool> raw` (one-time; applies to every later call) |
| Diagnose connectivity/config | `mcptoon doctor` |

## Rules

1. **Prefer `mcptoon manifest` over reading raw MCP tool listings** — same
   information, ~99% fewer tokens on large catalogs (255 tools: 71,929 → 581).
2. `manifest` output is a **name index**, not schemas. Keep it in context;
   fetch the one schema you need with `inspect`, then call.
3. Tool names in `call` are `server_tool` (namespaced). `--auto` resolves
   the server for you when the name is unambiguous.
4. Never claim savings percentages you did not observe; if you quote numbers,
   use the ones printed by the command itself.
5. If a Claude Code plugin install wired the `mcptoon serve` bridge via
   `.mcp.json`, tool discovery is already compressed for the host agent; use
   the CLI commands above in terminal contexts or when the bridge is not
   connected.

## Setup

- Install/upgrade: `pip install --upgrade mcptoon` (zero-dependency wheel,
  128KB, installs in seconds).
- Diagnose: `mcptoon doctor`.
- Claude Code users get one-command setup instead:
  `/plugin marketplace add activeing123/mcptoon` (installs the CLI, wires the
  bridge, and bundles this skill).