In addition to rating a freelancer or vendor based on their individual skills, it can be important to have a more broad rating system that your team can measure all freelancers and vendors against.
This is what Core Attributes are for. They represent the more general qualities your team desires from their flexible workforce. Examples include 'Culture fit', 'Timeliness', 'Communication' and 'Value for Money'.
Set these Core Attributes by going to the 'Admin' section at the top of the page and clicking the '+' icon next to 'Core Attributes'.