Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, and the description adds genuinely new behavioral context: this initiates real outbound phone calls for every configured scenario, a costly physical-world side effect. It still omits async behavior, whether the run can be cancelled/stopped, and whether it is idempotent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.