Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds one genuinely useful trait beyond the annotations: unauthorized related fields are masked in the response, which tells the agent that returned data may be partially redacted and not to treat absence of fields as an error. Annotations already cover read-only, idempotent, non-destructive behavior, so the remaining gap – what 'unauthorized' means and how a 404 is signalled – is a moderate one.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.