Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It discloses behavior beyond a simple 'lists tasks' by stating it returns 'all tasks you have submitted, newest first' and enumerates the result fields (id, status, description, result, timestamps). It does not mention authorization or pagination, but for a read-only, zero-parameter list tool this is reasonably transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.