Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already establish this as a safe, read-only, idempotent, open-world call, so the description is not obligated to restate that. It adds genuinely useful context the annotations do not: the credit cost ('Flat 5 points per successful run') and the shape of the returned profile. It stops short of describing rate limits or response format details.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.