The standards for a good breeder are pretty much the same. Responsible breeding makes a difference in the chances of a success match of dog to owner. Get the dog from a shelter or rescue. Since one does not pay by the word the best advertisements offer full details. A good advertisement, one that is very complete, is very educational about what one should expect from a responsible breeder.
Education is the primary role of the rec.pets.dogs.
A breeder who knows enough to carefully evaluate the parent dogs, and their pedigree, for sound genetic health and temperament understands that the information simply cannot be omitted from an advertisement. Thus if the information is missing it is likely because it does not exist. A good advertisement shows that the breeder used care and thought in the breeding decision. Nope, the owner who went to the trouble of keeping it in top condition would certainly advertise that fact. Similar principles apply to advertising puppies.