Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
There are 0 parameters, and the schema coverage is effectively 100% because none exist. The description adds no parameter meaning, but with no parameters to document, the baseline of 4 is appropriate. However, it could have clarified what the selection operates on, which it does not.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.