Dry snickerdoodles are usually the result of overbaking.  You should NOT pull your cookies out when they’re set and crispy. It’s best to slightly under bake the cookies, then let them finish cooking/firm up on the baking sheet after they’re removed from the oven.  Another culprit could be that there isn’t enough fat in the dough.  Either the recipe itself didn't call for enough fat (this recipe is perfect) or it was just measured incorrectly.