Utility MCP Tools v2

A utility MCP tool is a Workflow that performs one clear business action.

Shape the tool

For a query:

  • Use a verb-led tool name in the MCP Receive step, for example queryInvoices. Define the appropriate parameters for the tool.
  • Return a structured object (or list of objects nested within the root return object) via the MCP Respond step.

For a mutation:

  • Make the action explicit in the tool name.
  • Validate required identifiers and allowed transitions before calling the provider.
  • Support an idempotency or business key when the underlying system permits it.
  • Return deterministic not-found, conflict, validation, and dependency failures with IsError: true.

Authorize narrowly

Assign only the required Workflows to the Delegate MCP user API Key and permit only the intended users. Use Environment-specific Connections with least-privilege service identities. The agent never needs Connection credentials in its arguments.

Test and observe

Test the smallest safe mutation, retry, duplicate, and failure paths. Use meaningful Step names and retain enough non-sensitive context in logs to identify the caller's business key and outcome.

Prefer several focused tools over one generic “run operation” tool with a large mode enum. Focus improves discoverability, authorization review, and safe approval decisions.

See also