The usual rule of thumb is that if you can feel a scratch by rubbing your fingernail across the surface, you will be able to see the scratch after anodizing.
It is always helpful for the finisher to understand the application. It is also good for the finisher and client to agree on a viewing distance. If a part is to be viewed from 10 feet away or more, such as a window or roofing component, then the inspection may be relatively insensitive to scratches. However, if the part is to be viewed from 24″ or closer, then even a scratch that you cannot physically feel may be unacceptable.