Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema already documents booking_id at 100% coverage, so the baseline is 3. The description adds practical meaning by naming the exact display label 'Gondola booking', excluding hotel/airline confirmation numbers, and clarifying that email-imported reservations have no booking ID. These constraints go beyond the bare schema text.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.