Start with the business problem, not a feature list. Which people will use this, how many times a day, and what does the process look like without it? An experienced team who understands the goal often proposes a cheaper route to it; a team that receives only the requirements as given will price the list as written.
Describe the scope as concrete flows: a walk through each important path. Equally important, write down what the first release deliberately excludes. A written out-of-scope list saves more friction during acceptance than any other single page. Indicate as well which items are decided and which are still open — honest teams price those differently, and pretending everything is fixed helps nobody.
Set out your constraints. The list covers the platforms and services involved, the data you already hold and its condition, regulatory obligations, expected load, which devices matter and infrastructure that is already decided. If there is a hard date, say what depends on it: a team can often rearrange the plan to hit it, laravel vs wordpress performance but only if they know it exists.
Write down what done means feature by feature. Testable acceptance criteria do not need special syntax: a short paragraph setting out the expected behaviour is sufficient. This one section compresses the sign-off process dramatically and removes most late-stage disagreement.
To close, say what you expect back. Ask for an itemised estimate, laravel vs nextjs a written list of assumptions, whatever the team considers risky and a low number and a high number. Read a wide range as information, not evasion: it tells you the part of the brief that needs work. At that point tighten that section and request a revised number — the second estimate is far closer to reality.