Connect MCP tools

MCP supplies a protocol for discovering and calling capabilities. Connecting a server does not replace Cayu’s tool admission, execution, credential or environment policies.

Plan the boundary

1. Select the transport and trusted server identity.
2. Discover its tools and inspect their schemas.
3. Admit only the capabilities your application requires.
4. Classify effects and apply authorization before execution.
5. Provide scoped credentials through application configuration.
6. Bound call duration and result size, then retain useful evidence.

Treat descriptions and results from an external server as external content. A result that asks the agent to call another tool is not authority to do so.

Verify failure behavior

Test a missing server, invalid arguments, malformed results, timeouts and cancellation. Distinguish discovery failure from execution failure; avoid retrying an external mutation merely because its result was not observed. A receipt or idempotency check belongs to the application that owns that effect.

Configure integration construction in integrations/, tool registration in tools/, and policy in policies/. Use MCP API for the exact release-matched constructors and transport options, and durable service tools for external mutations.