So you're saying it would be useful for an "AI assistant" to ask you for the base each time you give it a math problem? Do you also want it to ask you if you're using the conventional definitions of "2" and "+"? For the car wash, would you like it to ask if you're on Earth or on Mars? Do you have air in your tires? Is the car actually a toy car?
Some assumptions are always necessary and reasonable, that's why I'm saying the "AI" lacks common sense.
And what if it’s a full service car wash and you’ve parked nearby because it’s full so you walk over and give them the keys?
Assumptions make asses of us all…