If i would examine the rope and a message shows "The rope is attached to a nearby stone and leads down into ground." Then i would assume "climb down" or "climb down the rope". But if the rope present in room actually makes the exit "down" available and i see it then i just type "down". "climb rope" is confusing isn't it? You can climb up or climb down the rope but that should be somehow pointing out in the description of rope or room that this action is indeed possible. Hang on (a rope joke lol). Maybe you could use it like this "climb rope down". But then it would be much more work in the code to say to player "which way up or down?" when they type "climb rope" and two ways are open.
Or you can still use my favorite command "use rope" and it is done. Don't throw stones at me Garry pls :D.