AKC is just a breed registry, not a mark of quality. A responsible breeder would want to assure that their breeding lines are clear of genetic health or temperament problems. Even if the parents are not affected doesn't mean the pups will be disease free. Remember the parents need only carry the genes. As many problems are not detectable before the dog is fully mature health guarantees for genetic disease are normally at least two years.
Many breeders guarantee against genetic disease for the life of the dog.
If certificates are issued provide the numbers so people can look into the history for themselves. A person who cares about the puppies they bring into this world tries to avoid having them die in shelters. There is a lot more information the educated potential puppy owner will want to know. However, the above information at least tells everyone that the breeder is caring and educated enough that the puppies are less likely to end up dying in a shelter somewhere. If these details are not provided, a buyer would do well to look for a responsible breeder elsewhere.