true, but in the pass/fail dynamic, making a bit of noise that causes the guard to investigate, but not find you is still a pass. also, all the circumstances present, play into the skill check target number, or any bonus/malus you have on the roll.
honestly the level of abstraction has to fit the tone and theme of the game, as well as the genre and intended playstyle. and even then, it could be determined by the scene or encounter, as well as the characters doing the stealthing.
for example; trained ninjas should be able to do simple checks for stealth, that is what they do, all day every day.