Open with the problem you are solving, not a list of screens. Which people will use this, how many times a day, and what happens today? A vendor who understands the goal will suggest a simpler way to reach it; one who only sees a feature list can only price your assumptions along with the work.

Set out the scope as user stories or scenarios: a walk through each important path. Every bit as useful, build an affiliate platform state explicitly what is out of scope. An explicit exclusion list saves more argument later than the rest of the brief combined. Also mark which items are decided and which may still change — honest teams price those differently, and pretending everything is fixed only hurts you.

Set out your constraints. This means existing systems the software has to talk to, the data you have and where it lives, regulatory obligations, expected load, which devices matter and any technology you are committed to. If there is a hard date, say why: a team can often cut the right scope to meet it, but not if the date is a secret.

Write down what completion means for the important items. Testable acceptance criteria need not use formal language: a short paragraph describing what a user should be able to do is sufficient. This single habit compresses the sign-off process considerably and removes most late-stage disagreement.

Finally, state what you want in the response. Require a task-level breakdown, hire apache http server developers the assumptions used, the main risks and an optimistic and a pessimistic figure. Read a wide range as information, not evasion: it normally identifies where your description is thin. Then tighten that section and ask again — the second estimate will be much more reliable.