Begin with the reason this software should exist, not a feature list. Who will use the system, with what frequency, and how is the job done today? An experienced team who knows what you are trying to achieve will suggest a cheaper route to it; someone handed only a feature list prices the list as written.
Set out the scope as concrete flows: a walk through each important path. Just as important, write down what you are not building. An explicit list of exclusions saves more friction during acceptance than the rest of the brief combined. Indicate as well which items are decided and which are still open — the difference changes the price, and pretending everything is fixed helps no one.
Write down the hard constraints. The list covers existing systems the software has to talk to, the data you have and where it lives, compliance requirements, traffic expectations, target platforms and infrastructure that is already decided. Where a date is genuinely fixed, say what depends on it: a good team is usually able to cut the right scope to meet it, but not if the date is a secret.
Say what the word done means for the important items. Testable acceptance criteria do not require special syntax: a short list describing what a user should be able to do will do. That one addition compresses the sign-off process dramatically time and materials contract closes off the usual argument at handover.
Finally, state what you want in the response. Request a breakdown by feature or module, the assumptions behind each number, the risks the team sees and an optimistic and a pessimistic figure. Read a wide range as a signal about the brief: kubernetes development company it usually points to where your description is thin. From there rewrite that part and ask again — the next version will be much more reliable.
