Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits. It mentions 'recompute', implying potential mutation, but doesn't confirm side effects, permissions, rate limits, or error conditions. The return structure is not described despite an output schema existing.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.