Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so all four parameters (line, brand, limit, since) are already documented with enums and formats. The description only echoes brand, product line, and date filtering without adding syntax or defaults, so baseline 3 is correct.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.