Open with the reason this software should exist, not a list of screens. What kind of user will use the system, how many times a day, and how is the job done today? An experienced team who understands the goal can propose a cheaper route to it; someone handed only a feature list prices exactly what you asked for.
Set out the scope as short scenarios: who does what, and what happens next. Equally important, state explicitly what the first release deliberately excludes. An explicit list of exclusions removes more friction later than the rest of the brief combined. Indicate as well which parts are firm and which are still open — honest teams price those differently, and concealing the open questions helps nobody.
Set out your constraints. These include systems you must integrate with, the data you have and where it lives, regulatory obligations, user volumes, supported browsers or devices and stacks you cannot change. If a deadline is real, say what depends laravel vs ruby on rails comparison it outsourcing dubai: a team can often cut the right scope to protect it, but only if they know it exists.
Say what completion means for the important items. Clear acceptance criteria need not use special syntax: a short list setting out the expected behaviour is enough. This one section reduces the review at the end dramatically and closes off most late-stage disagreement.
To close, ask for a specific format. Request a breakdown by feature or module, the assumptions used, the risks the team sees and a low number and a high number. Read a wide range as information, not evasion: it usually points to exactly which requirement is unclear. At that point tighten that section and request a revised number — the revised figure will be far closer to reality.