Direct answer
The short version.
A strong ad brief states one audience problem, one desired belief change, the proof available, the action required and the constraints that cannot move. It does not prescribe every frame before the creative team has solved the problem.
Key takeaways
Keep these three decisions.
- Define the belief change.
- Supply proof and non-negotiable constraints.
- Evaluate concepts by strategic difference.
The operating problem
Weak briefs are either vague collections of adjectives or miniature scripts disguised as strategy. The first produces generic work; the second removes the creative team's ability to find a sharper route. Both usually omit the evidence that must make the claim credible.
A practical system
Write the brief as a decision document: audience state, commercial objective, single-minded proposition, reasons to believe, mandatory facts, prohibited claims and measurement plan. Add two or three deliberately different territories the team may explore, then ask each concept to explain which belief it intends to change.
What to measure next
Judge the brief before judging the work. If proposed concepts are indistinguishable, the proposition may be too broad. If every concept requires new claims, the proof is incomplete. A good brief creates a range of ideas that can still be compared against one commercial objective.
Primary and authoritative references
Sources used for context.
Frequently asked questions
Two useful follow-ups.
How long should an ad brief be?
Long enough to remove strategic ambiguity and short enough to be used during production. One to three focused pages is usually more useful than a presentation full of background.
Should a brief include example ads?
Examples can clarify tone or production expectations, but they should not become instructions to copy another brand's idea.