/brainstorm

name: brainstorm
description: Optional divergent-then-convergent dialogue for fuzzy ideas. Invoked from the idea skill as a prelude to structured elaboration; produces one ElaborationRound of decision-point Q&A and returns control. Never writes files, never posts comments, never resolves elaboration.
license: AGPL-3.0
metadata:
  author: chorus
  version: "0.24.1"
  category: project-management
  mcp_server: chorus

Brainstorm Skill

A divergent-then-convergent dialogue cadence for ideas whose direction is still being formed. Compresses the conversation into one `ElaborationRound` of decision-point Q&A — same shape as a structured elaboration round, but the questions, options and answers are synthesized at the end of the conversation rather than asked up front.

This skill is a **producer** of one elaboration round; the **scheduler** decision (resolve vs. follow-up) belongs to the calling idea skill.

---

When invoked

Only as a sub-step of the idea skill, only after the user has explicitly opted in via `AskUserQuestion`. Never run standalone, never run without user opt-in. The expected entry point is the idea skill's "Step 4.5: Brainstorm Mode (Optional Prelude)" — see the idea skill for the surrounding flow.

---

Research boundary

Reuse the calling Idea's findings and follow `/skill:research` ([shared rules](../research/SKILL.md)); switching into brainstorm does not grant a second investigation. If the goal needed focusing first, after the user selects a direction and before synthesis, apply the caller's optional research decision once with that focus. Return any findings alongside the synthesized round for the Idea caller to persist. Research does not choose the user's direction, remove the opt-in/selection gate, write files/comments, or resolve elaboration.

Hard rules

1. **One question at a time.** Each `AskUserQuestion` call MUST contain exactly one question entry. Wait for the answer before asking the next. 2. **Multi-choice preferred.** Frame each question as 2-4 options where possible. Open-ended is acceptable when options would be premature, but lean toward concrete choices. 3. **Propose 2-3 directions before stopping divergence.** Once the requirement direction is clear enough to enumerate, present 2-3 distinct approaches in a single `AskUserQuestion`. Mark exactly one as the recommended option per the host tool's `AskUserQuestion` recommendation convention (the spec does not dictate a specific marking format — follow the tool's documentation). 4. **Explicit user approval required to exit divergence.** Do NOT proceed to synthesis until the user has selected one of the proposed directions. 5. **No files written.** Do NOT write any markdown, design doc, scratch file, or any other file to disk. The conversation produces an `ElaborationRound` and nothing else on disk. 6. **No comments posted.** Do NOT call `chorus_add_comment` from this skill. Comments belong to the idea skill or the user, not to the brainstorm step. 7. **No design-doc handoff.** Do NOT invoke any skill whose purpose is to produce a design document or implementation plan. The brainstorm output is the synthesized round — there is no separate doc. 8. **No `validate_elaboration` call.** Do NOT call `chorus_pm_validate_elaboration` from this skill. Whether to resolve the elaboration or open a follow-up round (`chorus_pm_start_elaboration` again) is the calling idea skill's decision, not this skill's.

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Step-by-step

1. Gather context

Before asking the first divergent question, read the idea and surrounding project state. Mirror the idea skill's gather-context list:

chorus_get_idea({ ideaUuid })
chorus_get_documents({ projectUuid })
chorus_get_document({ documentUuid })   # for any document worth reading in full
chorus_get_proposals({ projectUuid, status: "approved" })   # to understand patterns
chorus_list_tasks({ projectUuid })   # to avoid duplicating existing work
chorus_get_comments({ targetType: "idea", targetUuid: ideaUuid })

Skim each result for: stated background, stated requirements, stated constraints, and what is conspicuously NOT stated. The gaps are the questions worth asking.

2. Divergent Q&A

Ask one question at a time via `AskUserQuestion`. Aim to surface:

• The **goal** the idea is trying to serve (often more abstract than the idea statement).
• The **constraints** that exclude entire branches of solution space (deadlines, compatibility, scope).
• The **success criteria** — how will the user know this is done.

Keep each question single-purpose. If you need to ask three things, that is three rounds, not one combined `AskUserQuestion`.

3. Propose 2-3 directions

When the goal, constraints, and success criteria are clear enough that you can name distinct approaches, present them in a single `AskUserQuestion`:

AskUserQuestion({
  questions: [
    {
      question: "<the convergence question>",
      header: "<short header>",
      options: [
        { label: "Option A (Recommended)", description: "<what + tradeoff>" },
        { label: "Option B", description: "<what + tradeoff>" },
        { label: "Option C", description: "<what + tradeoff>" }
      ],
      multiSelect: false
    }
  ]
})

The recommendation must be visibly marked to the user using the host tool's `AskUserQuestion` convention. State **why** you recommend it — usually a sentence about the dominant tradeoff.

4. Wait for explicit approval

Do not proceed to synthesis if the user has not selected one of the options. If the user picks "Other" with free text, treat that as a new constraint — go back to step 2 or step 3 with the refined direction.

5. Synthesize decision-point Q&A

For each material decision the user made during the conversation, build one `ElaborationQuestion`. A "material decision" is a moment where the user chose between alternatives or set scope explicitly. Map each decision per the synthesis spec below.

6. Persist the round

Call `chorus_pm_s