Your script must include a title, a list of characters, a clearly described setting, and carefully considered stage directions. If ever in doubt about these elements, and how they work together, refer to the script of a contemporary play. (Do not copy their format. Use the format I have suggested, because published plays use a different format).
Your 10-minute script can either be a complete work, with formal closure, or part of a larger work that you hope to write. Either way, avoid too much introductory, expository material. Plunge us straight into the action and do your best to allow the reader/audience to figure out what is happening. (Avoid explaining). As you write, keep asking yourself:
What do these characters want?
How does this further the story?
What is at stake?
Aristotle argued that character is revealed through action, and that a play that revolves around character alone is boring. He is also argued that audiences care most when they are moved to pity and fear. (He was talking about tragedy. It’s fine for you to write a comedy or a musical).
