Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations present, the description must carry the full behavioral burden, but it only lists event categories. It does not disclose whether polling is blocking or non-blocking, whether events are consumed/cleared, whether a debug session must be active, or how errors/timeouts are handled.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.