You can get away with a short denouement, if you want to pull it off. But the climax of the story should be a drama with a length that fits the rest of the story.
In particular, if the story does not turn around the question of "How do we find out this information?" having a character figure out what to do should lead to a difficult process of putting it into effect. Preferably with some weaknesses discovered along the way. If the reveal of the knowledge is not the climax, having a character just do it is anticlimax.
A short story, of course, especially one's that short, should either start with the knowledge, or make it the main question. To keep it short. 0:)