A lets B sign a NDA/NC and then shares its ideas.

How "broad"/"general" can these ideas be to not be considered confidential?
E.g. the idea that A tells B is this: "Making an app similar to *x* but with a better UX and simpler design." without getting into details, **how** it can be done more intuitive/simpler.

Can this idea be protected by the NDA/NC without any details about _how_ you could reach this goal?