A brief has four parts: role, goal, context and format. Typing "summarise this" supplies one of them, which is why the summary comes back fine and useless.
The model reads your contract faster than you do and catches things you would miss at the end of a long day. It also knows nothing about your business, your suppliers, or what you would call a good answer. A brief closes that gap, the same way it would for somebody on their first morning.
Who is reading this, and with what eyes. A careful owner. A bookkeeper double-checking the numbers. A sceptical lawyer.
What you want at the end, named. Every deadline. The risks. A shorter draft.
What is true that the document does not say. New supplier. Two-person team, no legal staff. Worried about getting locked in.
What the answer should look like. A bulleted list under each heading, with the section number beside every item.
Four lines, two minutes, and the same four lines work on every document of that kind from here on.
A brief reads: 'You are a careful owner with no legal staff. Tell me the deadlines and the risks in the attached contract.' Which part is missing?
Role
Context
Format
Role and context are both there, and the goal is named. Nothing says what the answer should look like, so you get a shape chosen by the model rather than a list you can scan and check.