What
A subagent is a helper agent that Claude Code starts for a task, and its definition can list MCP servers (add-ons that give extra tools). Those servers are now skipped if they have not been approved for the current project. Claude Code reports them as "missing project approval (approve via /mcp)". Before, only servers blocked by a managed policy were kept out.
Why
An agent defined in a project you have not approved can no longer quietly connect its own MCP servers. To use them, approve them with /mcp.
Names in the bundle/mcp
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on Edit docker-compose.yaml: increment the integer in the setup service's touched a line naming /mcp after this was published.
The **Needs certificate** badge next to the tunnel's name goes away once a certificate is registered. See [Add a CA certificate](https://platform.claude.com/docs/en/agents-and-tools/mcp-tunnels/console#add-a-ca-certificate).agents-and-tools/mcp-tunnels/deploy-compose see the edit
Confirmed since
Anthropic's documentation has since written up /mcp, on Error reference.
* For other reserved names to avoid, see [MCP configuration warnings](/docs/en/mcp#configuration-warnings)errors see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up /mcp, on Error reference.