Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds real value by disclosing a functional limitation (no conference filtering, with the reason: missing conference metadata on current-season records). It says nothing about authentication, rate limits, or whether the 'season' input actually narrows the returned list.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.