Open with the business problem, not your preferred technology. What kind of user will use the system, how many times a day, and what does the process look like without it? A vendor who understands the goal often proposes a simpler way to reach it; a team that receives only the requirements as given can only price your assumptions along with the work.
Define what is included as concrete flows: who does what, and kotlin development services what happens next. Every bit as useful, write down what is out of scope. A written out-of-scope list saves more friction at delivery time than the rest of the brief combined. Indicate as well which items are decided and which are still open — the difference changes the price, hire developers in saudi arabia and hiding it helps nobody.
List the constraints. The list covers existing systems the software has to talk to, the data you have and where it consulting services lives, regulatory obligations, expected load, supported browsers or devices and stacks you cannot change. If there is a hard date, explain what drives it: an experienced team will often rearrange the plan to meet it, but only if they know it exists.
Write down what the word done means feature by feature. Acceptance criteria do not require special syntax: a plain-language note stating what a user should be able to do is sufficient. This single habit reduces acceptance testing dramatically and closes off most late-stage disagreement.
Finally, ask for a specific format. Require an itemised estimate, the assumptions behind each number, enterprise web application development the risks the team sees and a low number and a high number. Take a broad range as information, not evasion: it tells you the part of the brief that needs work. At that point tighten that section and ask again — the second estimate is far closer to reality.