Exactly, so one of the ratings can be do they answer phones? do they publicly share their policies?
I can't see this happening unless there is major consumer demand/outcry about this. Certain agencies are extremely transparent, while others are less so.
As far as consumer demand, it's enough to look at how centered on Kashrus the advertisements of Pesach programs are, to realize that the consumer focus isn't there.
One way this might happen would be if serious agencies would actually use and promote the use of "Member AKO" as part of their logos/certifications, and AKO in turn would have (they might, at least to a certain extent) required training, certification, continued education for various types of mashgichim.