Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds a meaningful behavioral guarantee: 'Does not bid or pay.' This clarifies there are no financial side effects, which is valuable context beyond the generic read-only annotation. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.