MCP Server Tool-Spec Writer Prompt

Write an MCP tool spec for the capability below.
Include: tool name (snake_case), a one-line description, JSON Schema for input (with required fields and constraints), JSON Schema for output, error codes, and idempotency notes.
Then write the single instruction an agent would receive to know when to call it vs. an alternative.

Capability: {{capability}}

Replace the {{fields}} with your own context and tighten the rules to match your domain.