Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations cover the safety profile (readOnly=false, destructive=false, idempotent=false), so the description only needs to add context — and it does: it discloses the shared/cross-platform nature, the default read_write invite scope, and what is returned. It stops short of stating error behavior (e.g. duplicate-name rejection) or any permission/rate constraints, but the added context is substantial.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.