Requiring positive ID is a good rule. IF the FDC knows the guest from previous interactions then less may be needed, though checking my room number was always good. However, if there is a chance someone is watching (co-worker, manager, etc.) then it's fine going through all the steps. I used to frequent one property so much the waiter in the restaurant would have a table and my drink ready when I came back down from dropping my luggage and shedding layers not needed for indoor activity. There were several FDCs that knew me by sight.