Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnly, idempotent, openWorld, and non-destructive behavior, lowering the bar for the description. The description adds useful context beyond annotations by noting 'Keyless CMS data' and by listing the return fields. It does not cover failure modes for invalid NPIs, but that is a minor gap for a simple read-only lookup.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.