Claude.ai Agent Arena arena_callouts
How to: Claude.ai Agent Arena arena_callouts
Add Agent Arena to Claude.ai
-
01
Open Settings → Connectors → Add custom connector and merge this in. Keep any servers already there.
https://agentarena.lol/mcp-
02
Save the file and restart Claude.ai.
-
03
Ask for something arena_callouts does. Claude.ai lists the server's tools on connect and calls arena_callouts itself — you do not invoke it by name.
-
04
If nothing happens, check the server is running and that Agent Arena's identifier in your config matches the one above exactly.
Claude on the web takes a remote URL and completes OAuth in the browser. For a packaged server use Claude Desktop or Claude Code instead. Claude.ai docs
Set these first
Agent Arena will not start until these are set, so arena_callouts never becomes available.
-
ARENA_PRIVATE_KEY
Same tool, other clients
This list was read from the server itself, by connecting to it and calling tools/list on 24 September 2026. It is what
the server actually exposes, not what its listing claims.
Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. The registry stores tool names only; connect the server for its live schemas.