Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds nothing behavioral beyond that (no indication of what the state snapshot contains, freshness, or whether it can be empty), so it contributes little that the annotations don't.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.