Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so all five parameters are already documented at the schema level. The description largely restates the schema's tag_ids and source guidance (at-most-one, empty clears, where to find source/source_id) rather than adding new semantics, so the baseline 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.