Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the schema already documents goal, members, and department, including the omit-members-when-using-department rule and the department match/refusal behavior. The description's 'Name attendees or pass a department' largely restates what the schema provides, so the baseline 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.