As it stands if you want the scheduling server to be able to access TFS you need to set the scheduling server service login credentials to your TFS credentials as detailed in this telerik documentation http://docs.telerik.com/teststudio/features/scheduling-test-runs/change-service-account) . However in certain instances it is not possible due to domain issues to get this to work.  So it would be nice to have the scheduling sever use a set of credentials for logging into TFS that are separate from the credentials used to startup the scheduling server service.