Hi there Jake! You have to remember that you are trying to think like a costumer. Your tags should appeal to the masses, they're not supposed to keep you out of the search. If someone was to be looking for a case, they will search for a smartphone case, iphone case, iphone 4 case, metal phone case, customized case, personalized case, plastic case, silicon case, thin case, waterproof phone case, etc.
Remember, think like them!