Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the description's added value is the payload shape: it names the five returned attributes and explains that 'namespace' is the form's unique id used for dispatching. That is real behavioral context beyond the structured fields, though ordering and pagination behavior remain unstated.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.