Start with the reason this software development outsourcing usa should exist, not your preferred technology. What kind of user will use this, how often, and what happens today? An estimator who knows what you are trying to achieve will suggest an alternative that costs less; one who only sees a feature list prices exactly what you asked for.
Set out the scope as concrete flows: what the user does and what the system does in response. Just as important, blockchain development company state explicitly what you are not building. An explicit exclusion list prevents more friction during acceptance than the rest of the brief combined. Also mark which items are decided and which are still open — the difference changes the price, and hiding it helps nobody.
Write down the hard constraints. The list covers the platforms and services involved, the data you already hold and its condition, security and compliance rules, traffic expectations, target platforms and stacks you cannot change. If a deadline is real, say why: a good team is usually able to resequence the work to meet it, but only if they know it exists.
Define what done means feature by feature. Clear acceptance criteria need not use any formal notation: a short list stating what a user should be able to do will do. This single habit shortens the review at the end by a surprising margin and removes the most common source of disputes.
To close, say what you expect back. Ask for an itemised estimate, the assumptions behind each number, the main risks and an optimistic and a pessimistic figure. Treat a wide range as useful information rather than evasion: it normally identifies where your description is thin. Then tighten that section and request a revised number — the next version tends to be far closer to reality.