Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
readOnlyHint=true already tells the agent this is a safe non-destructive read. The description adds genuine context beyond that by enumerating what the payload contains (status, output, task history) and the underlying endpoint, but says nothing about missing-id errors or auth requirements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.