Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds nothing beyond that — it doesn't say what a 'cascade' returns, what object graph is traversed, or whether the 'preview' is computed live. A 2 reflects that the fragment is barely more informative than structured fields alone.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.