I think you're seeking "fit for use" = quality, instead. This is closer to the parent comment.
Adding extra things is necessarily exceeding specifications.
If the spec calls for a car, and I give you a car with a roof-rack, then I've exceeded the specification for what the car must do. Whether that's an improvement is subjective. If you don't need the rack, then your MPG suffers.
I think you're seeking "fit for use" = quality, instead. This is closer to the parent comment.