A great brief is not a summary of your idea; it is a set of constraints that prevents “helpful drift.” Decide who the reader is (job title or situation, not demographics), what changes after reading, and what the reader can do next with your guidance. Then set scope boundaries as exclusions. For example: if you’re writing about productivity for managers, explicitly state what you will not cover (e.g., detailed personal habit coaching, software feature reviews, or company-wide HR policy changes).
To make the brief actionable, include a short promise statement and a “source material” paragraph. The promise tells the model what success looks like (the reader will be able to run X process with Y inputs). The source material paragraph is where you list your own examples, frameworks, or interview notes the model must reuse rather than reinvent. This is how you preserve authorship while still accelerating structure and drafting. If you do not have personal examples yet, write placeholders in the brief (for instance: “Insert your example of a weekly planning meeting here”). The goal is to give the model something to align with, then replace placeholders during the voice and verification passes.