Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, so the safety profile is known; the description adds real value by spelling out downstream effects (subscribers blocked, invitations stopped, issue delivery paused) and that the stored password is erased. It stops short of saying whether this is reversible or needs re-authentication to reconnect.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.