Start with the business problem, not a feature list. Which people will use this, outsource laravel development with what frequency, and what happens today? A vendor who understands the goal will suggest an alternative that costs less; one who only sees a list of screens will price exactly what you asked for.
Describe the scope as concrete flows: fintech app development services what the user does and outsource react native development what the system does in response. Every bit as useful, write down what you are not building. An explicit list of exclusions prevents more disagreement at delivery time than almost anything else in the document. Indicate as well which decisions are settled and which are still under discussion — honest teams price those differently, and hiding it helps no one.
Set out your constraints. This means systems you must integrate with, the data you already hold and its condition, regulatory obligations, expected load, which devices matter and infrastructure that is already decided. If there is a hard date, say why: a good team can often cut the right scope to meet it, but only if they know it exists.
Define what done means for each item. Acceptance criteria do not need formal language: a short paragraph setting out what a user should be able to do will do. This single habit compresses the sign-off process by a surprising margin and eliminates most late-stage disagreement.
To close, say what you expect back. Request an itemised estimate, the assumptions used, the main risks and a range rather than a single figure. Take a broad range as useful information rather than evasion: it tells you exactly which requirement is unclear. Then tighten that section and ask for a new estimate — the revised figure is far closer to reality.