Start with the reason this software should exist, not a feature list. Which people will use the system, with what frequency, and hire node.js experts what does the process look like without it? An experienced team who grasps the purpose will suggest a simpler way to reach it; a team that receives only a list of screens will price your assumptions along with the work.
Define what is included as user stories or scenarios: a walk through each important path. Just as important, write down what you are not building. An explicit exclusion list saves more argument later than the rest of the brief combined. Also mark which decisions are settled and hire crm developers which are still under discussion — honest teams price those differently, and hiding it helps nobody.
List the constraints. The list covers systems you must integrate with, the data you have and where it lives, security and azure development agency compliance rules, user volumes, supported browsers or devices and infrastructure that is already decided. Where a date is genuinely fixed, say what depends on it: an experienced team is usually able to rearrange the plan to hit it, but not if the date is a secret.
Say what done means for each item. Clear acceptance criteria do not need any formal notation: a plain-language note stating what must be true when the feature works is sufficient. That one addition compresses the review at the end considerably and eliminates the usual argument at handover.
Finally, say what you expect back. Ask for a task-level breakdown, a written list of assumptions, the risks the team sees and a low number and a high number. Read a wide range as useful information rather than evasion: it normally identifies the part of the brief that needs work. At that point clarify that area and request a revised number — the next version tends to be the one worth planning around.