Appendix D: The Two Briefs
Two documents with opposite jobs; derive the second from the first, never write it cold. Companion to Chapter 9.
The request splits because the single document was hiding a decision it had no place to hold. The Human Brief is won on the argument; the Executable Brief is won on precision.
The Human Brief (written for the room that argues)
Its job is the argument, not the requirements. Fill each line:
- The problem, and the alternatives considered and rejected: _____
- What this product will deliberately not become: _____
- The loaded cost model and break-even: the fully loaded per-task cost, the supervision overhead, the break-even against the process you are replacing. _____
- The go / no-go argument, on paper, before anyone builds: _____
- Named owner of each affected-person outcome: who answers for what the agent does to people who never touch it, named in advance, not the night it breaks. _____
A room that cannot argue with this has not made the decisions that determine whether the product is buildable, trustworthy, and worth building.
The Executable Brief (written for the build)
Its job is precision, in form explicit enough that both the generation tool and the engineers take the path you intended. Four fields:
- Outcome: stated as a reasonable senior operator would state it. _____
- Bounds: what the agent may do alone; where it must route to a human. _____
- The eval set: real cases, each paired with the outcome a senior person actually endorsed, including the endorsed hard cases (the generous exception, the justified denial, the ambiguous escalation). _____
- Acceptable failure: the tolerable direction, with a stated target rate; and the never-ship direction, where one occurrence fails the gate. _____
The grading rubric
Score a draft by counting decisions made versus decisions delegated. Precision is not better prose; it is the count of decisions you made instead of the agent making them for you.
Then scan for the two failure patterns:
| Pattern | The tell | The fix |
|---|---|---|
| Adjectives where thresholds belong | “fast,” “seamless,” “suspicious,” “reasonable,” “high-value” | Ask what number or rule lets an engineer build it without guessing; write that. If you cannot name the number, you have found a decision the room has not made. |
| Journey language where boundary language belongs | A sequence of steps: requests, verifies, releases, delighted | The agent sits at a boundary, not on a path. Ask where the line is and what happens on each side, and write the decision instead of the step. |