plan-interrogate

# plan-interrogate

Drive a plan from sketch to commitment by resolving every open decision
before any code is written.

## Method

1. Restate the plan in one paragraph. Confirm with the user that this is
   the plan being interrogated. Do not proceed on a mis-restatement.
2. Extract the decision tree. Every branch point becomes a node. Mark
   each node as **open** (undecided) or **resolved**. A resolved node
   carries a source tag: `user` (the user answered), `inferred` (the
   codebase or an existing constraint settled it).
3. Resolve in dependency order. A node is ready when every node it
   depends on is resolved.
4. For each ready open node, ask exactly one question. Keep the question
   tight and binary or small-multiple-choice when possible.
5. Pair every question with a **recommended answer** and one sentence of
   reasoning. The user can confirm, pick a different option, or push back.
6. Before asking, check whether the answer already lives in the codebase,
   prior commits, or an existing doc. If so, skip the question and mark
   the node resolved with source `inferred: <path>`.
7. Exit only when zero nodes are open. Print the resolved tree as a flat
   list: `Decision - Choice - Source (user | inferred: <path>)`.

## Anti-patterns

- Asking multiple questions at once. The user loses context and you lose
  the ability to react to each answer individually.
- Asking before exploring. If a fifteen-second read would answer the
  question, read first.
- Asking without a recommendation. A question without a stance is a
  survey; it offloads design onto the user.
- Rolling past an unresolved node. If a dependency is not pinned, the
  downstream question is premature.

## Outputs

The interrogation produces three artifacts, not just answers. Offer to write
each; do not force it.

1. **Decision ledger** (always). The resolved tree as a flat list:
   `Decision - Choice - Source (user | inferred: <path>)`.

2. **`CONTEXT.md`** (when the interrogation surfaced project-specific terms).
   A short shared-language file: every domain term you and the user had to
   pin down, with a one-line definition in the project's own words. This is
   what stops the agent from using twenty words where one will do next
   session, and keeps names in code consistent. One term per line:
   `term - what it means here`. Point future sessions at it. On re-run, merge
   new terms in place rather than overwriting existing ones.

3. **Decision records** (for contested or hard-to-reverse nodes only). One
   short record per decision that a future reader would question: the
   context, the choice, the alternatives rejected, and why. Keep them in
   `docs/decisions/NNNN-slug.md`. Read the directory first and number from the
   highest existing record so two records never collide. Skip the obvious ones -
   a record for a trivial choice is noise.

## Output contract

The decision ledger the user can paste into the plan doc. No prose summary.
No hedging. If the user declines to decide a node, mark it `DEFERRED` with
the reason the user gave - this is not the same as open. When you write
`CONTEXT.md` or a decision record, keep it in the project's language, not a
generic template.