For some validations we should gather additional info from the API that can be used for debug. An example came up recently with the "Minimum disks required" validation. The request was:

"I had a host whose disk was too small, but I couldn't see this without doing a curl and looking at the inventory.  I know it's not the most comfortable for you to get that information, but it would be nice to expose to the user (if the "Minimum disks of required size" validation fails, show the eligibility property of the disks?)"