Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only supply readOnlyHint=false, so the description usefully clarifies that the underlying instance is unaffected by the detach. It says nothing about session-side effects (whether the connection is re-establishable, whether any local state is lost, or required auth), leaving gaps for a mutation of connection state.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.