Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already convey that the tool is readOnly, idempotent, and non-destructive, so extra credit is given for any increment beyond that. The description adds that the tool returns 'how to use them' along with the capabilities list, but it does not explain any behavior around the optional userId, response shape, or conditions under which the listing might be server-driven or personalized. It is not contradictory and does add some content scope, but it is a baseline behavioral disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.