Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already indicate readOnly and idempotent behavior, and the description adds that it does not fetch evidence or invoke a model, reinforcing the non-destructive, side-effect-free nature. This goes beyond the annotations by clarifying the absence of external calls and model inference, which is valuable for an agent deciding whether to use it.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.