In most cases there is a possibility to comment your answer. If a comment is marked with an asterisk (*), then adding a comment is mandatory, otherwise it is optional.
But as added comments are important for the organisation, we recommend you to add descriptive comments at least for those questions that you feel are important.
When commenting please try to describe examples to explain the numerical assessment and express your expectations. Describe the daily / routine situation and try to avoid highlighting individual exceptional cases.