Does brief length matter? What does a good brief look like?
The short answer: brief length barely affects the result. Plan Mode is built to fill in missing detail through conversation. A 1-sentence brief with clear intent produces nearly the same plan as a 2-page brief — but the long brief saves you 3–5 rounds of clarification.
The thing that matters is what you write, not how much.
What Plan Mode does with a short brief
Brief: "Test sparkling coffee new product."
Plan Mode asks: "Who exactly? What aspects — acceptance, pricing, packaging? Any constraints?" You answer in 2 minutes, plan is generated. Total: 5 minutes.
What Plan Mode does with a detailed brief
Brief: "We're launching a zero-sugar sparkling coffee, positioned as healthy energy drink. Target: 25-35 year-old female office workers in tier-1 cities. Main competitors: Starbucks, Manner, Genki Forest. Want to understand acceptance of the sparkling+coffee combo, optimal pricing across ¥15/¥18/¥20, whether health or social positioning works better, and packaging considerations."
Plan Mode asks 0–1 confirmation questions. Plan is generated immediately. Total: 2 minutes.
Both produce a usable plan. The detailed brief saves you a chat round. It does not produce a meaningfully different plan — Plan Mode follows the same research design logic either way.
The parts that actually move the needle
When AI builds a research plan, the inputs that change the output most are:
Target audience specificity. "25-35 year-old female office workers in tier-1 cities, regular coffee drinkers, health-conscious but not extreme" produces a meaningfully different persona set than "young women." The more concrete the segment, the better the persona selection.
What you want to learn. "Will users accept this concept" is vague. "What price point maximizes adoption" is specific. The second produces questions that actually surface useful answers.
What you already know. Mention your pricing hypothesis, your competitive context, any past findings. AI builds on what you have rather than starting from zero.
Constraints. Budget cap, deadline, must-include competitors. These shape the plan structure, not just the plan content.
Briefs that don't work
Too vague. "Help me understand my customers" — AI has no idea where to start and will spend rounds clarifying.
Too long. 2,000 words of background with 30 questions — AI will pick 3–5 questions anyway and ignore the rest. The remainder is wasted typing.
Assumes the answer. "Confirm that users like our product" — AI won't validate a leading question. Rephrase as "What do users actually think of our product?"
No target audience. "Run a study" — AI will pick a default, which is almost certainly wrong for you.
Mentions a framework without a question. "Use the Jobs To Be Done framework" — framework alone doesn't help. You also need to say what you want to learn.
Three brief templates that cover most cases
Product testing brief
Example:
User insights brief
Example:
Market opportunity brief
Example:
Good vs bad in one comparison
Bad brief: "Test our new product."
Good brief: "We're testing a zero-sugar sparkling coffee with 25-35 year-old female office workers in tier-1 cities. We want to know if the sparkling+coffee combo reads as appealing or weird, what price feels reasonable, and whether the health positioning or the 'afternoon energy' positioning lands better. We've never sold coffee before and our competitors are Starbucks RTD and Genki Forest."
The second brief is 3 sentences. It's not long. It's just specific.
Editing your brief after Plan Mode starts
You can edit your brief mid-conversation. If you said something wrong, or AI is heading in a direction you don't want, just correct it. Plan Mode updates its understanding from your latest message.
If you realize after starting a study that the brief was wrong, you can't change the brief — but you can start a new study with a corrected brief. The first study's results are still saved; you don't lose them.
Related: Plan Mode, Interview, Discussion