Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The tool has zero parameters, so the schema is empty. The baseline for 0 parameters is 4. The description adds meaningful context about the tool's output (source, date, licence, citation), which is valuable beyond the empty schema. It does not need to explain any parameters because there are none.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.