Sometimes when occupancy rates allow for it, we don't book until we inspect a room. Every hotel allows this before you pay, and if you don't like it, just walk away. You can come back if you discover the place was the best option, so don't say anything negative before you size up the local situation. Also, don't hesitate to barter at the front desk before you say "yes".
Have specific questions ready when you call. It's OK to ask about the last remodel, age and firmness of beds, and all that's important on your list.