I'm sorry, without the actual short description of the story, it's difficult to provide a full story. However, if the short description mentions a conflict, like a character vs. character or character vs. nature, we can build on that. We could introduce more characters who are related to the conflict, maybe some are allies and some are obstacles. And then describe how the main character uses his or her skills or resources to deal with the situation.
Sure. But since you haven't given the short description, I can't really do it specifically. Generally, if we have a short description, we can expand it by adding more details about the characters, their motives, and the setting. For example, if the short description is about a hero's journey, we can start from his ordinary world, talk about the call to adventure, his refusal at first, and then how he overcomes challenges and finally returns home changed.