Build the thing you can explain.
Explaining the offer can reveal disagreement about who does what. A clear promise still needs a reason for someone to want it.
"It has automation, integrations and customizable workflows" can accurately describe a product that nobody in the room understands in the same way. One person imagines beginners who want the work done for them. Another imagines experts who need control over every step. Both agree to the feature list. They have not agreed to the business.
A useful explanation starts with the person and the moment. Someone is trying to do a particular job. Something makes it difficult. The product changes part of that situation. What remains their responsibility should be clear too, especially when a polished demonstration makes it easy to overlook.
Imagine a scheduling service. "Your appointment is booked" and "Your preferred times have been sent" describe different obligations. The first requires a confirmed place in someone's calendar. The second leaves a response pending. A feature list could describe either product. Choosing the promise determines what the business still has to provide after the customer presses the button.
Writing this early makes disagreement cheaper. Assumptions that might otherwise emerge during development become visible in a paragraph. The answers influence controls, onboarding, support and price. They should also help the team decline a feature that serves a different customer or creates a responsibility it cannot meet.
An explanation is still a hypothesis
A clear promise is useful for finding disagreement inside the team. It is not proof that anyone wants the offer. A service can be coherent, well explained and unnecessary. After writing the explanation, put it beside a real task someone is trying to complete: does the promised outcome solve the part they need help with and what would they have to give up to adopt it?
A complicated service may need different accounts for different audiences. The descriptions should connect, so that understanding the short version does not require unlearning it when the details arrive. They should also exclude something. When an attractive feature serves a different promise, the team has a reason to question it before building.
That leaves an explanation with a useful but limited place in building a business. A team can finally agree on what 'booked' means and still have more to learn about why someone would choose the service. We like the clarity of that position. The promise has become specific enough for someone outside the team to judge it.