Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 0% for the 'days' parameter, so the description must compensate. It does by explaining the timeframe context ('over the last N days'), which directly maps to the parameter meaning. For a single simple parameter, this is sufficient compensation, though it could be more explicit by naming the parameter directly.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.