Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds nothing beyond the word "preview" – no statement of what the cascade info contains, what is affected downstream, or whether it is a dry run of a destructive operation, which is the critical question here.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.