A support agent has a tool whose entire description is "Queries the v2 inventory microservice via internal gRPC." The agent often skips it when customers ask whether an item is in stock. What is the best change to the description?

Answer: A — State what it returns, accepted SKU formats, an example query, and when to use another tool

The current description explains implementation, not purpose. A description that states what the tool returns, the input formats it accepts, an example query, and its boundary with similar tools is what the model needs at selection time (a). Error codes (b) and a bare response schema (c) don't say when to use the tool. Keyword stuffing (d) is fragile and still omits inputs and boundaries.