Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare the write/read/idempotency profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the description needn't restate safety. It usefully adds that a later report replaces the earlier one (one counted result per person per story), the honesty requirement, and the 'apply no fix' constraint — behavioral context beyond the structured fields. It stops short of describing attribution or downstream effects of a recorded result.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.