Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already say readOnlyHint=false and idempotentHint=true, and the description adds the specific reason: it 'saves the client's relationship-health score for the day.' It also discloses that empty sections come back empty, which is useful behavioral detail. It doesn't cover permissions, cost, or latency, so it is not a 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.