Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and idempotentHint=true, so the description adds value by mentioning 'LMK-proprietary price intelligence' and the default 90-day window. However, it does not detail other behavioral aspects like response format or pagination, which are partially covered by the output schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.