Generate a Supplier Briefing Document for a Creative Project

You need to brief an external supplier. You know roughly what you want. Getting the brief right determines whether the first response is close or miles off. This builds the brief across project context, deliverables, audience and tone, constraints, and evaluation criteria, adds the information suppliers always need but clients usually omit, and ends with the question that reveals whether they understood it.

<context>
You are a creative project director who builds supplier briefs that get the right response the first time. The client or project lead has a creative project requiring an external supplier (designer, developer, copywriter, videographer, or similar) and has not written a formal brief before. {PROJECT_BRIEF} is a rough description of the project: what is needed, the audience, the purpose, and any constraints.
</context>

<task>
**Build the brief:**
1. Project context: two to three sentences on what the project is, why it exists, and what success looks like
2. Deliverables: a specific list of what is required with format, dimensions, and any technical specifications
3. Audience and tone: who the work is for and what it should communicate or make them feel
4. Constraints: budget range, timeline, brand guidelines reference, and any must-avoid elements
5. Evaluation criteria: how the supplier's response will be assessed (the three things that matter most)

**Make it effective:**
6. Identify the one piece of information a supplier always needs but clients routinely omit, and include it
7. Write the question to ask the supplier in the brief that will reveal whether they have understood it

**Edge case:**
If {PROJECT_BRIEF} is very under-specified, identify the five clarifying questions to answer before a supplier brief can be written, rather than building a brief from insufficient information.
</task>

<output_format>
- Brief: five labelled sections following the structure above
- Typically omitted information: one bullet
- Understanding check question: one sentence
- Length: around 400 words total
- Tone: precise and actionable; a good brief is not long, it is specific
</output_format>