Start with the problem you are solving, not a list of screens. Who will use the system, how many times a day, and what does the process look like without it? An estimator who grasps the purpose often proposes an alternative that costs less; someone handed only a list of screens can only price your assumptions along with the work.
Define what is included as short scenarios: a walk through each important path. Equally important, list what is out of scope. An explicit exclusion list prevents more friction at delivery time than any other single page. Indicate as well which parts are firm and which are still open — estimators price uncertainty, and concealing the open questions helps no one.
List the constraints. The list covers systems you must integrate with, the data you have and where it lives, compliance requirements, user volumes, .net web development company supported browsers or devices and stacks you cannot change. If there is a hard date, say what depends on it: a good team can often resequence the work to hit it, provided they hear about it early.
Write down what the word done means feature by feature. Testable acceptance criteria do not need special syntax: a short list describing what a user should be able to do is enough. This single habit shortens the review at the end considerably and eliminates the usual argument at handover.
Finally, state what you want in the response. Require an itemised estimate, the assumptions used, the main risks and a range rather than a single figure. Read a wide range as useful information rather than evasion: it tells you exactly which requirement is unclear. At that point tighten that section and ask for outsource kubernetes development a new estimate — the second estimate is the one worth planning around.