Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable context beyond that: it explains that it returns connection URLs and how the response varies (authenticated true vs connect_url), which is not in the annotations. It doesn't contradict annotations, though it leaves ambiguity about partial connection states.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.