Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/openWorld/idempotent/non-destructive, and the description adds genuinely new behavioral context: an outbound HTTP GET, auth options, approximate cost, and the payment_required return case. It does not contradict the annotations and gives the agent a fuller operational picture.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.