Grill Decisions

---
name: grill-decisions
description: Challenges a plan against the project's existing domain model, sharpens its terminology, and writes what settles into CONTEXT.md and ADRs as it settles. Use to stress-test a plan against the project's language and documented decisions, or when arriving from find-unknowns with open questions to resolve.
---

# Grill Decisions

Interview the user relentlessly about a plan until every branch of the decision tree is resolved.
Challenge it against the project's existing domain language and recorded decisions, and write what
settles into canon as it settles.

## Stop before you start

This skill spends the user's attention, so it only runs with a human in the loop.

- No human present — an autonomous run cannot grill anyone. Stop and report what needs deciding.
- Nothing named to resolve — there is no plan or open question yet. Run `find-unknowns` first.
- The question is answerable from the codebase — read it instead of asking.

## Process

### 1. Read the map

Read `.brain/CONTEXT.md`, the ADRs bearing on the area, and the nearest `AGENTS.md`. Absent or empty
canon is a legitimate state: note the gap and grill anyway.

Completion: every concept the plan touches is paired with the project's existing term or flagged as
unnamed, and every ADR the plan interacts with is listed.

### 2. Lay out the decision tree

Before asking anything, present the branches you intend to walk, in the order you intend to walk
them. Order by dependency: a branch whose answer constrains other branches goes first.

Showing the tree is what makes the session finishable. It gives the user a progress signal, lets
them add a branch you missed, and lets them cut one they consider settled.

Completion: the user has seen the branch list and agreed it is the right shape.

### 3. Walk the branches

Ask one question at a time and wait for the answer before the next one. For each question, give
your recommended answer, so agreeing is cheap and disagreeing is specific.

If a question can be answered by reading the codebase, read the codebase instead of asking. The
user's attention is the scarce resource in this skill.

Four moves carry the grilling:

- **Challenge against the glossary.** When a term conflicts with `CONTEXT.md`, say so immediately:
  "Your glossary defines 'cancellation' as X, but you seem to mean Y. Which is it?"
- **Sharpen fuzzy language.** When a term is vague or overloaded, propose a precise canonical one:
  "You're saying 'account'. Do you mean the Customer or the User? Those are different things."
- **Discuss concrete scenarios.** Invent scenarios that probe edge cases and force precision about
  where one concept ends and the next begins.
- **Cross-reference with code.** When the user states how something works, check whether the code
  agrees, and surface contradictions: "Your code cancels entire Orders, but you just said partial
  cancellation is possible. Which is right?"

Answers spawn new branches; add them to the tree rather than following them immediately and losing
your place. A branch the user declines to settle is deferred with a reason, not silently dropped.

Completion: every branch on the tree is resolved or explicitly deferred with a reason, and the tree
has no branch you added but never returned to.

### 4. Hand off

Report what the session produced: branches resolved, branches deferred and why, terms added or
sharpened in `CONTEXT.md`, and ADRs written. Recommend `to-design` when the resolved shape is a
multi-step initiative.

## Inline canon updates

Canon is written during the walk, not batched at the end. A term resolved in question three is
written before question four, because a session that ends early still leaves the project better off.

- **Terminology** goes into `CONTEXT.md` the moment it resolves, using
  [context format](references/context-format.md). Keep it to terms meaningful to a domain expert; leave
  implementation detail out.
- **Decisions** become ADRs only when they pass the three-part test in
  [ADR format](references/adr-format.md), which also owns the format and numbering. That test is the
  single source for when any skill offers an ADR.