Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the baseline is 3. The description adds a specific list of accepted place types (IATA or name, parks, trailheads) and clarifies that the query should be just a place name, not personal information. This enriches the parameter's semantics beyond the schema examples.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.