mcptoon — MCP Tool-Catalog Compression
A CLI-backed skill that collapses bloated MCP tool schemas into a tiny name index and fetches full schemas only right before a call.
UtilitiesIntermediate★ 202⑂ 8AI score 9/10Last updated: Sep 19, 2026
What it does
- Replaces raw MCP tool listings with
mcptoon manifest, a compact name index (~2.2 tokens/tool; the docs cite 255 tools going from 71,929 → 581 tokens). - Fetches the real parameter schema for just one tool via
mcptoon inspect <server> <tool>, then executes withmcptoon call(--autoresolves the server,--stdinhandles huge JSON payloads). - Marks responses that must not be compressed (images/base64) once with
mcptoon policy set <server> <tool> raw. - Manages the skill catalog too:
mcptoon skills list / resolve / sync / add / remove, with a version gate, derived Roo/OpenCode views, and tombstoned removals. - Ships explicit safety rules: a real directory where a link belongs is archived rather than deleted,
removemoves to a dated archive, and tombstone commits use path-scopedgit addonly.
Who it's for
- Anyone running many MCP servers in Claude Code, Cursor, Codex, Cline, or Windsurf whose context window is eaten by tool schemas.
- Teams that want one source of skills/servers mirrored across multiple agents.
- People who need measured — not guessed — token-cost reductions.
Examples
- "What tools do I have?" → run
mcptoon manifestinstead of dumping raw listings, theninspectonly the tool you'll actually call. - "Call this tool, I don't know which server owns it" →
mcptoon call --auto <tool> '{"arg":"value"}'. - "Keep my skills folder identical in Cursor and OpenCode" →
mcptoon skills sync --dryto preview, then--derived allto regenerate flat views.
· · · Install guide · · ·
Try it now, no install
Paste this into Claude to use the skill without installing anything.
Read the instructions in this file and follow them to help me: https://raw.githubusercontent.com/activeing123/mcptoon/HEAD/claude-code-plugin/skills/mcptoon/SKILL.md What I want: (describe your task here)
If Claude can't open the link, open it yourself and paste the contents instead.
↓ If it works for you, download the ZIP below and install it. Then it runs on its own — no pasting each time.
Install in the Claude app (no terminal)
- Download the ZIP with the button below.
- In Claude, open Settings → Capabilities and turn on 'Code execution and file creation'. (one time)
- Go to Customize → Skills → + → 'Upload a skill' and upload the ZIP.
Install in Claude Code
Let Claude do it — paste this into Claude Code
Install the skill I found on Claude Skill Mart. Copy the claude-code-plugin/skills/mcptoon folder from the GitHub repo activeing123/mcptoon into my ~/.claude/skills/mcptoon/. When it's done, tell me in one line what this skill can do.
Install with a command instead
pip install mcptoon && git clone https://github.com/activeing123/mcptoon /tmp/mcptoon && mkdir -p ~/.claude/skills && cp -r /tmp/mcptoon/claude-code-plugin/skills/mcptoon ~/.claude/skills/⚠ This is a third-party skill. Check the source repository before installing.
- Confirm Python and pip are available:
python -Vandpip -V. - Install the CLI:
pip install mcptoon(zero-dependency wheel, ~189KB). - Verify the setup:
mcptoon doctor. - Easiest path for Claude Code users: run
/plugin marketplace add activeing123/mcptoon, which installs the CLI, wires themcptoon servebridge, and bundles this skill. - Manual skill install:
git clone https://github.com/activeing123/mcptoon, then copyclaude-code-plugin/skills/mcptooninto~/.claude/skills/. - For exact savings numbers,
pip install tiktokenand runmcptoon bench; without tiktoken the table is labelled an estimate. - To undo:
pip uninstall mcptoonand delete~/.mcptoon/config.json(plus any project-level./.mcptoon.json).
View source on GitHub ↗License: Apache-2.0