Open with the problem you are solving, not a feature list. Who will use this, how to choose the right software development partner many times a day, and what happens today? A vendor who understands the goal will suggest a simpler way to reach it; a team that receives only the requirements as given prices the list as written.
Set out the scope as user stories or scenarios: who does what, domain expertise software development company and what happens next. Every bit as useful, write down what is out of scope. An explicit list of exclusions removes more friction at delivery time than almost anything else in the document. Mark too which items are decided difference between livewire and alpine js which are still under discussion — estimators price uncertainty, and concealing the open questions helps nobody.
List the constraints. The list covers systems you must integrate with, the data you already hold and its condition, compliance requirements, expected load, which devices matter and stacks you cannot change. If there is a hard date, explain what drives it: an experienced team will often rearrange the plan to meet it, provided they hear about it early.
Define what completion means for the important items. Clear acceptance criteria do not require any formal notation: a short list describing the expected behaviour is sufficient. That one addition reduces acceptance testing by a surprising margin and eliminates most late-stage disagreement.
Finally, ask for a specific format. Ask for a breakdown by feature or module, 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 usually points to exactly which requirement is unclear. From there rewrite that part and request a revised number — the second estimate will be the one worth planning around.