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 correctly specifies the order of subtraction (second from first) but does not mention any behavioral traits like error handling, integer overflow, or return type, though the output schema likely covers the return type. The description is adequate for a simple pure function.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.