The brief decides the project before it starts
Agencies answer the brief they are given. A website brief that lists pages and features gets you proposals that price pages and features, and a site that looks fine and sells nothing. A brief that explains the business, the buyer and what the site has to make happen gets you proposals that disagree with each other about approach, which is exactly what you want to see, because that is the moment you learn which agency understands the problem.
Start with why you are doing this now
One paragraph, and it is the most important one. Something changed: you are entering a new market, the current site was built for a company you no longer are, sales keep sending PDFs because the website cannot explain the offer, traffic arrives and does nothing. Whatever it is, write it plainly. Agencies that solve business problems will build their whole response around this paragraph. Agencies that do not will skip past it to the page list, which tells you something useful for free.
Describe the buyer, not the audience
Everyone visiting the site is not an audience worth designing for. Name the people whose decision matters: what they do, what they are worried about, what they are comparing you against, how they found you, and what they need to see before they will get in touch. If several kinds of buyer matter, rank them, because a homepage cannot lead with three messages. This section is where most briefs are thinnest and where the resulting site is weakest.
Say what the site has to make happen
Define success in terms someone can check. More enquiries from a particular kind of company. Fewer calls asking a question the site should answer. Shorter sales conversations because the buyer arrives informed. A specific action completed more often. Vague goals like a modern presence produce vague work, and they make the result impossible to judge later. If you cannot name the action you want a visitor to take, the project is not ready to brief.
Be honest about content
Content delays more website projects than anything technical. Say what exists, what needs rewriting, what has to be created from nothing, and who inside your company will write or approve it. Photography counts: if you plan to use stock images of people who do not work for you, say so, because it changes what the design can do. An agency that knows the content situation can plan around it. One that assumes it exists will build a site that stays empty for four months.
Separate the essential from the wished-for
Write down what the site has to do beyond publishing pages: languages, a product catalogue, a booking flow, gated documents, a form that lands in your CRM, a portal for existing clients. Mark each one as needed at launch or wanted later, because that single distinction moves more scope than any other line in the brief. Include the systems it has to connect to and who runs them, and mention anything you already know is awkward.
Constraints, decisions and dates
Say who signs off, and keep that list short, because a project with six approvers moves at the speed of the slowest one. Give the real deadline and what is driving it, whether that is a trade show, a launch or a contract ending. Name the platform if you are committed to one and explain why, or say you are open. Mention what you cannot change: the CMS your team already knows, the hosting your IT department insists on, the domain arrangement you are stuck with.
What to leave out
Do not specify the design. Sending a few sites you like is useful; sending layout instructions is not, because you are paying for judgement you then prevent anyone from using. Do not write a page-by-page sitemap unless the structure is genuinely fixed, since how the content gets organised is part of the work. Skip the technical architecture unless you have a real constraint. Describe the problem, the buyer and the outcome in detail, and leave the solution to the people you are hiring to find it.
Written by
Idennex
Strategy-first agency, Istanbul