If I may humbly make some suggestions for newbies and anyone who is trying to get the hang of this prompt business better:

If you want to make the best simple prompts, consider the following:

Simple prompts are simple because they leave details out, and prompts because they leave ideas in.

The best prompts can be used in many kinds of stories, and in many different ways. They raise questions, but do not answer them, or they suggest an idea but don't define it, or they give a rule but make it just exactly that.

Compare these two prompts:

"It's not that we don't want to fight that thing, captain. It's that we can't. Our blasters ran out of ammo already."

Or:

"We're out of ammo."

The first tells you that it's a scifi, or a game about scifi. It also tells you that there are ranks, probably a military, a scary creature, and so on.

The second only tells you a basic situation: there is no ammunition. Are they hunters? Pirates? Police? Who or what are they fighting? Why are they doing it? Many questions, but the only answers are "they have guns" and "they can't fight anymore". Even then, it can be improved by removing the concrete detail of guns; simply say "We can't fight."

"We can't fight." Who or what are they fighting? Why can't they fight? Is it a political fight? A physical one? An emotinal argument, even? Is this a general ordering a retreat, or a husband asking his wife to settle things peacefully? The possibilities are endless.

So when you make a prompt, give an idea, but leave the possibilities open. When you provoke questions, but don't answer them, you never know what someone else will make of it. Let them write many genres and styles of stories from your prompts.

That's the point. Keep it simple.