Begin with the reason this software should exist, not a feature list. What kind of user will use it day to day, with what frequency, kubernetes web development company and how is the job done today? An experienced team who grasps the purpose will suggest a simpler way to reach it; one who only sees the requirements as given will price the list as written.
Set out the scope as concrete flows: what the user does and what the system does in response. Equally important, state explicitly what the first release deliberately excludes. An explicit list of exclusions removes more friction during acceptance than the rest of the brief combined. Mark too which parts are firm and which are still open — honest teams price those differently, and pretending everything is fixed only hurts you.
Set out your constraints. The list covers systems you must integrate with, existing databases and their quality, best python development company regulatory obligations, expected load, target platforms and any technology you are committed to. If a deadline is real, say why: a good team is usually able to resequence the work to meet it, provided they hear about it early.
Say what the word done means for each item. Acceptance criteria do not require special syntax: a short list stating what a user should be able to do is enough. That one addition reduces the sign-off process considerably and removes the most common source of disputes.
Finally, state what you want in the response. Ask for a breakdown by feature or module, the assumptions used, the risks the team sees and a range rather than a single figure. Take a broad range as a signal about the brief: it normally identifies exactly which requirement is unclear. From there clarify that area and ask for a new estimate — the revised figure is far closer to reality.