Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known before reading the text. The description reinforces this with 'Permanently' and 'cannot be undone', which is modest added value, but it says nothing about required permissions, whether dependent data (leads, logs, broadcasts) is cascaded, or how failures are reported.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.