Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds useful provenance (Daily Treasury Statement) and unit clarification (millions of dollars), but does not describe the shape of the returned data, ordering, or how the limit parameter affects results. There is 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.