Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must carry the parameter meaning. It does so by providing the valid range (1..365), the default (30), and the effect on the result (market movement over the period). It does not clarify the odd string typing of the parameter, but it provides substantial semantic value.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.