Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is clear from structured data. The description adds nothing about behavior—no mention of rate limits, response shape, or what a 'channel' entails. For a read-only list operation, annotations carry most of the burden, but the description still offers no supplementary context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.