Begin with the reason this software should exist, not a feature list. What kind of user will use this, symfony vs spring boot with what frequency, and what does the process look like without it? An experienced team who knows what you are trying to achieve can propose an alternative that costs less; someone handed only a feature list can only price the list as written.
Describe the scope as concrete flows: a walk through each important path. Just as important, hire eas developer write down what the first release deliberately excludes. A written out-of-scope list saves 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 hiding it only hurts you.
Write down the hard constraints. This means systems you must integrate with, the data you already hold and its condition, security difference between livewire and alpine js compliance rules, traffic expectations, target platforms and stacks you cannot change. Where a date is genuinely fixed, say what depends on it: a good team can often rearrange the plan to protect it, provided they hear about it early.
Say what done means feature by feature. Acceptance criteria do not require special syntax: a plain-language note stating the expected behaviour is sufficient. This single habit shortens the sign-off process by a surprising margin and eliminates the most common source of disputes.
Finally, ask for a specific format. Request an itemised estimate, a written list of assumptions, the main risks and a range rather than a single figure. Take a broad range as a signal about the brief: it usually points to the part of the brief that needs work. Then tighten that section and ask again — the revised figure tends to be much more reliable.
