Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It describes the core behavior (subtraction) and return value, but doesn't disclose additional traits like error handling for non-numeric inputs, precision limits, or performance characteristics. It's adequate but lacks depth.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.