Begin with the problem you are solving, not a feature list. What kind of user will use this, with what frequency, and what happens today? An estimator who understands the goal will suggest an alternative that costs less; someone handed only a list of screens can only price the list as written.
Describe the scope as user stories or scenarios: who does what, and what happens next. Every bit as useful, list what you are not building. An explicit list of exclusions removes more argument later than almost anything else in the document. Indicate as well which items are decided and which may still change — estimators price uncertainty, and concealing the open questions only hurts you.
Write down the hard constraints. This means the platforms and services involved, existing databases and their quality, security and compliance rules, traffic expectations, supported browsers or devices and infrastructure that is already decided. Where a date is genuinely fixed, say what depends on it: an experienced team will often rearrange the plan to meet it, provided they hear about it early.
Define what the word done means for each item. Acceptance criteria do not need formal language: livewire vs alpinejs a short list stating what a user should be able to do is enough. This one section compresses acceptance testing considerably and custom ecommerce development eliminates the usual argument at handover.
One last thing, say what you expect back. Request a breakdown by feature or module, the assumptions used, whatever the team considers risky and a low number and aws development services a high number. Read a wide range as information, not evasion: it outsourcing dubai normally identifies the part of the brief that needs work. At that point tighten that section and ask for a new estimate — the next version tends to be the one worth planning around.