Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate. Although watchId is not explicitly documented, 'Deletes a competitor watch' makes the parameter's semantic role unambiguous: watchId identifies which competitor watch to delete. For a single, trivially inferable string parameter this is sufficient compensation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.