Open with the reason this software should exist, not a feature list. which is better laravel or symfony people will use this, how often, and what happens today? A vendor who grasps the purpose often proposes a simpler way to reach it; a team that receives only a list of screens can only price exactly what you asked for.
Define what is included as user stories or scenarios: who does what, and what happens next. Equally important, list what the first release deliberately excludes. A written out-of-scope list prevents more disagreement during acceptance than the rest of the brief combined. Mark too which items are decided and which contract model for software development may still change — estimators price uncertainty, and pretending everything is fixed helps nobody.
Write down the hard constraints. The list covers existing systems the software has to talk to, the data you already hold and its condition, security and compliance rules, alpine js vs livewire expected load, which devices matter and infrastructure that is already decided. Where a date is genuinely fixed, say what depends on it: a team can often resequence the work to meet it, provided they hear about it early.
Define what the word done means feature by feature. Acceptance criteria do not need special syntax: a short paragraph describing what a user should be able to do will do. That one addition shortens the sign-off process dramatically and alternative to laravel removes the usual argument at handover.
Finally, state what you want in the response. Request an itemised estimate, a written list of assumptions, whatever the team considers risky and an optimistic and a pessimistic figure. Treat a wide range as a signal about the brief: it normally identifies exactly which requirement is unclear. From there tighten that section and ask for a new estimate — the next version tends to be the one worth planning around.