How to Write a Dev Agency Brief That Actually Gets You What You Want

Start With the Problem, Not the Solution

The #1 brief mistake: leading with feature lists before explaining what problem you're solving and for whom. Agencies that get a feature list without context can't make smart architectural decisions or flag scope that doesn't serve your goal. Three sentences about your user and their problem before any feature is mentioned. Example: 'Dog owners in cities struggle to find trusted last-minute walkers. They currently use Facebook groups and call friends. We want to build a platform where they can book verified walkers in under 5 minutes.' From this, we know the target user, the current behavior, and the success metric.

• Who is the primary user? What are they doing today instead?
• What is the one thing they accomplish with your app that they can't do now?
• How will you know the MVP worked? (signups, revenue, retention rate — one metric)
• What's the business model? (how does money flow?)

Write User Stories, Not Features

Instead of 'user authentication,' write: 'As a dog owner, I can sign up with my email and create a profile including my dog's name, breed, and temperament so that walkers know what to expect.' Instead of 'booking system,' write: 'As a dog owner, I can see available walkers near me, select a time slot, and pay via card so that I have a confirmed walk scheduled in under 3 minutes.' User stories force you to define the actor, the action, and the outcome — which is exactly what engineers need to estimate accurately.

Specify What's Out of Scope

This is as important as what's in scope — and most briefs skip it entirely. List what you're explicitly not building for v1. This prevents misunderstandings where the agency assumes something is included that you never intended. 'Out of scope for v1: in-app video calls, recurring bookings, multi-city support, subscription plans, iOS widget, background location tracking.' A clear out-of-scope list signals that you've thought about scope discipline — which agencies take as a strong signal you won't blow up the scope mid-build.

Reference Apps You Like (and Why)

Don't say 'like Uber but for dogs.' Do say: 'The booking flow should feel like Uber's — minimal screens, single primary action per screen, no registration required before seeing available walkers. The walker profile should be like Airbnb's — photo-forward, review-led, with social proof front and center.' Specific references + specific reasons help the agency calibrate UX expectations before design begins.

Include Platform, Timeline, and Budget Constraints

Agencies need to know: what platforms (iOS, Android, web — all three means 3× the work), whether you have a hard deadline (investor demo, launch event), and what budget range you're working with. You don't need to say the exact number, but 'budget is under $5K' vs. 'budget is $20–50K' completely changes the proposal. Agencies that don't ask about budget before sending a proposal are either going to overshoot or send a one-size-fits-all quote.

• Platforms: iOS only, Android only, both, web, PWA?
• Hard deadline: do you have one? Is it flexible?
• Budget range: be direct — it saves everyone's time
• Existing assets: do you have a design, codebase, or tech infrastructure already?

The Brief Template (Copy This)

Problem: [One paragraph about user, problem, current behavior]. Target user: [Primary persona in one sentence]. Core user story: [Three to five user stories in 'As a [user], I can [action] so that [outcome]' format]. Success metric for v1: [One number — signups, revenue, retention]. Out of scope for v1: [Explicit list of what's not included]. Reference apps: [Two to three apps + specific elements you like and why]. Platforms: [List]. Timeline: [Target launch date or flexibility window]. Budget range: [Honest range]. Existing assets: [Design files, codebase, accounts, APIs].