Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=false, so the write/safety profile is covered. The description adds nothing beyond that – no indication of what a run is, whether it starts an async job, whether it needs an existing session, or what happens on repeat calls (relevant given non-idempotency).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.