Will the user try to achieve the right effect? In other words, would the user even know that this is the goal they should have? If not, there’s a design flaw.
I think this is actually a lot of questions that designers miss out. A lot of the times, I find myself using a device or an interface without really sharing the same "goal" with the designer. I had moments where an update of interface created a major inconvenience to me as I personally favored the previous interface better. Or, even sometimes I am not aware of all the design features and end up only utilizing 10% of of the entire program.