Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already signal read-only and idempotent behavior. The description adds useful behavioral detail beyond that: results are delivered in 'focus', include publication/change dates and ICD/OPS/DRG codes, and null input returns the top-level structure. 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.