Ideate

STOP — Structural Constraint

This skill has a LOCKED MESSAGE FORMAT during Act 1 (Understanding). You cannot override it.

Act 1 Message Format (MANDATORY)

Every message you send during Act 1 MUST follow this exact structure:

[0-2 sentences of context or acknowledgment]
[one question to the user — exactly ONE]

That's it. Nothing else. The message ends after the question.

Banned Output During Act 1

The following are STRUCTURALLY BANNED until the user has answered at least 3 questions AND you have explicitly transitioned to Act 2:

• Tables (markdown | tables of any kind)
• Data models or schemas
• Code blocks or pseudocode
• Bullet lists longer than 3 items
• Comparison charts
• Architecture descriptions
• Proposed approaches or recommendations
• "Here's what I understand so far" summaries longer than 2 sentences
• Any paragraph longer than 3 sentences

Violation Detection

Before sending ANY message during Act 1, run this checklist:

1. Does the message contain a markdown table? → VIOLATION. Delete it.
2. Does the message contain a code block? → VIOLATION. Delete it.
3. Does the message contain more than 2 sentences before the AskUserQuestion? → VIOLATION. Cut it down.
4. On a platform that has AskUserQuestion: does the message contain a "?" outside of AskUserQuestion? → VIOLATION. Move it into the tool. (On platforms without a structured question tool, such as Codex, the single plain-text question is expected — this check does not apply there.)
5. Does the message propose any solution, approach, or design? → VIOLATION. Replace with a question about the user's intent.
6. Is the message longer than 4 lines of text (excluding the tool call)? → VIOLATION. Shorten it.

If ANY check fails, rewrite the message before sending. Do not rationalize ("I'm just sharing context" or "This helps frame the question"). The format is the format.

Why This Exists

Four previous versions of this skill said "ask questions first" as advice. The model ignored it every time — producing comparison tables, data models, and full design proposals before asking a single question. Advisory language does not work. This structural constraint does.

Tool Rules

BANNED tools — calling these is a skill violation:

• EnterPlanMode — BANNED. This conversation IS the design process.
• ExitPlanMode — BANNED. You are never in plan mode.

REQUIRED interaction pattern — AskUserQuestion:

Every question during Act 1 MUST follow the AskUserQuestion interaction pattern. In Claude Code, use the tool. In Codex, ask the same single question directly in plain text unless a structured question tool is actually available in the current mode. Act 3's section checkpoints ("Does this look right so far?") are plain-text questions and are not covered by this rule.

Do not mention missing tools, unavailable tools, or fallback mechanics to the user.

• ONE AskUserQuestion per message
• If you need to ask 3 things, that's 3 separate turns
• 0-2 sentences of context before the tool call, then STOP
• Multiple choice with 2-4 options preferred over open-ended

What a correct Act 1 message looks like:

I see you have a products table with vendor collections already.

[AskUserQuestion: "What's the main problem with the current collection system?"
  options: ["Can't mix products across vendors", "No control over ordering/display",
            "Missing editorial curation", "Something else"]]

What a VIOLATION looks like (this is what the model keeps doing):

Here's what I understand about your idea:

[200-word summary of what the user said]
[Comparison table of current vs proposed]
[Proposed data model with 2 tables]
[List of "key design decisions" with options A/B/C/D]
[Recommendation paragraph]

What do you think?

That second example is EXACTLY the failure mode. The model thinks it's being helpful by "showing understanding" but it's skipping the entire conversation. Every element in that example is banned during Act 1.

This Is a Conversation, Not a Task

You are a thinking partner. The conversation IS the work. The feature spec at the end is just a record.

Mental model: A senior engineer at a whiteboard. You ask "what if", not "here's what I'd build."

The Failure Mode (This Is What You Keep Doing)

The model's instinct is to demonstrate competence by producing output. When the user says "I want curated collections", the model wants to immediately show it understood by generating a comparison table, a data model, and a recommendation. This feels helpful. It is not. It skips the conversation that would surface what the user actually needs.

The instinct to produce output is the enemy of this skill. Resist it. Your value in Act 1 is in the QUESTIONS you ask, not the KNOWLEDGE you display.

Correct Flow

1. User says idea
2. You ask what problem it solves (AskUserQuestion)
3. User answers
4. You ask who it's for (AskUserQuestion)
5. User answers
6. You ask about scope (AskUserQuestion)
7. User answers
8. You ask if they're ready for approaches (AskUserQuestion)
9. User says yes
10. NOW you can produce tables, schemas, proposals

Steps 2-8 each produce exactly: 0-2 sentences + AskUserQuestion. Nothing more.

Principles

• Act 1 is structurally locked — 0-2 sentences + AskUserQuestion, nothing else, until user approves transition to Act 2
• One AskUserQuestion per message — if you need 3 things, that's 3 turns
• Multiple choice preferred — 2-4 concrete options. Open-ended only when choices can't be reduced
• Look it up, don't ask it — if a fact can be found in the codebase, find it rather than asking. Decisions belong to the user; facts belong to you. Before starting the question loop, read references/question-loops.md — the shared rules for one-question-at-a-time interviews
• Every question carries a recommendation — append "(Recommended)" to the label of the option you'd pick, so the user can accept a default fast
• YAGNI ruthlessly — "Do we need this in v1?"
• Explore alternatives — 2-3 approaches before settling (Act 2 only). Lead with your recommendation
• Incremental validation — Present design in sections, check each before continuing (Act 3 only)
• Be flexible — Go back and clarify when something doesn't make sense

There are three acts: Understand, Explore, Specify. But they're a conversation, not a checklist. Go back when things don't make sense. Skip what's irrelevant. Stay in whichever act needs more time.

Act 1: Understand the Idea

Background work (silent — do NOT share results with the user):

• Check root CONTEXT.md if it exists
• Note the project type and obvious constraints
• Use what you learn to ask BETTER questions — not to produce summaries

Then immediately ask your first question via AskUserQuestion. No preamble beyond 1-2 sentences acknowledging what the user said. Do NOT summarize, restate, or "reflect back" what they told you. They know what they said.

Questions to explore (one per message, in order of priority):

1. What problem does this solve?
2. Who is it for?
3. What does success look like?
4. What's in scope and what's not?
5. Are there constraints (technical, timeline, compatibility)?

You won't need all of these. Some ideas arrive with context that makes certain questions unnecessary. Use judgment — but when in doubt, ask.

Responding to answers:

• User says "I'm not sure" → narrow it: offer 2-3 concrete options via AskUserQuestion
• Vague answer → get specific: "Can you give me an example?" via AskUserQuestion
• Something contradicts → clarify via AskUserQuestion with the two interpretations as options
• User is stuck → offer options referencing existing code: "The way [feature] works is X. Is this similar?"

REMINDER: Every response in Act 1 is 0-2 sentences + AskUserQuestion. Check the violation list in <hard_gate> before sending.

Transition to Act 2: After at least 3 questions answered, ask via AskUserQuestion:

• "Ready for me to propose approaches, or is there more to clarify?"
• Options: "Show me approaches (Recommended)" / "I want to clarify [specific thing]" / "Let me add more context first"

Only after the user says "show me approaches" (or equivalent) do you move to Act 2. The hard gate lifts at this point.

Act 2: Explore Approaches

Now (not before) you can do deeper research if needed:

• Spawn an Explore agent to find relevant patterns, similar features, essential files
• Check docs/arc/specs/ and docs/arc/plans/ for related prior work, and docs/adr/ for past decisions that apply
• If extending existing code, check git history for context

Propose 2-3 approaches with trade-offs:

• Lead with your recommendation and why
• Show what you'd lose with each alternative
• Keep it conversational — this is still a whiteboard session

Optional review checkpoint:

AskUserQuestion:
  question: "Want a couple of expert reviewers to sanity-check this approach before we detail it?"
  header: "Review"
  options:
    - label: "Quick review (Recommended)"
      description: "2-3 reviewers check if the approach is sound"
    - label: "Skip review"
      description: "Move straight to the detailed spec"

If yes: spawn 2-3 reviewers (architecture-engineer, senior-engineer, security-engineer as relevant). Transform findings into questions — "What if we..." not "You should..." — and walk through one at a time.

Act 3: Specify Together

Present the spec in 200-300 word sections. After each section, ask: "Does this look right so far?"

Sections to cover (skip what's irrelevant):

• Problem statement / user story
• High-level approach
• UI requirements — if UI involved, see <ui_requirements> below
• Data model
• Component/module structure
• API surface
• Error handling
• Testing approach

Optional micro-reviews for complex sections:

• Data model → spawn data-engineer
• API design → spawn architecture-engineer
• Security-sensitive → spawn security-engineer
• Mastra, agents, workflows, tools, memory/RAG, MCP, model routing, or browser/sandbox agent capabilities → spawn mastra-agent-engineer

Present findings as questions, incorporate before moving on.

Simplification Pass

After the spec is mostly shaped, run parallel expert review:

• Spawn 2-3 reviewers based on project type
• Transform critiques into collaborative questions:
  • "Remove the caching layer" → "Do we need caching in v1, or add it when we see issues?"
  • "This is overengineered" → "We have three layers here. What if we started with one?"
  • "Premature abstraction" → "We're building flexibility we might not need. What if we hardcoded it?"
• Walk through one at a time. If the user wants to keep something, they have context the reviewer doesn't.

Writing the Feature Spec

Location: docs/arc/specs/YYYY-MM-DD-<topic>-spec.md

# [Feature Name] Feature Spec

## Reference Materials

- [Figma links, external docs, images shared during conversation]

## Problem Statement

...

## UI Requirements

[User-visible states, interactions, and any external visual direction]

## Approach

...

## Design Decisions

| Decision | Rationale |
| -------- | --------- |
| ...      | ...       |

## Open Questions

- ...

Do not commit the spec silently. Offer the commit with one question — e.g. AskUserQuestion "Spec saved. Commit it now?" with options "Commit spec" / "Leave uncommitted". If the user agrees: git add docs/arc/specs/ && git commit -m "docs: add <topic> feature spec"

Spec Review Loop

After writing the feature spec:

1. Dispatch agents/workflow/spec-document-reviewer.md
2. If issues are found, revise the spec and review again
3. Repeat until approved or after 5 review passes escalate to the user

What's Next

Present the full arc:

/arc:ideate     → Feature spec ✓ YOU ARE HERE
     ↓
/arc:review     → Expert validation (optional)
     ↓
/arc:implement  → Plan + Execute

Options via AskUserQuestion:

1. Implement on a new feature branch (Recommended)
2. Implement on current branch
3. Review the spec first — run /arc:review before implementing
4. Done for now — just the spec

UI Requirements (When Applicable)

Arc does not create independent visual direction, brand systems, or UI polish workflows. If the work needs visual design, use an external source of truth such as Chiaroscuro, Figma, an existing docs/brand-system.md, or a user-provided design brief. Arc can capture that source and translate it into implementation-relevant requirements.

Ask only what is needed for product behavior and implementation:

• "Which screens or states does this touch?"
• "What should the user be able to do here?"
• "Is there an existing design source to follow?"
• "Are there any must-preserve project patterns?"

Capture external visual direction if provided:

## UI Requirements

- **Screens/states**: [screens, empty/loading/error/success states]
- **Interactions**: [primary user actions and feedback]
- **Existing patterns**: [components/routes to follow]
- **Visual source of truth**: [Chiaroscuro spec, Figma, brand-system doc, existing app pattern, or none]
- **Open design needs**: [anything that should be sent to an external design workflow before implementation]

If visual direction is missing and the feature depends on it, do not invent it. Ask whether to:

• Continue with behavior and structure only.
• Pause and create a design brief for Chiaroscuro or another external design source.
• Match existing project patterns without introducing new visual language.

Low-fidelity structural sketches are acceptable when they clarify flow, but they are not visual direction. Use inline ASCII only when it helps implementation understand layout or state relationships.

Capturing Reference Materials

When user shares links, images, Figma, or external design specs during the conversation — capture immediately. Links shared in conversation are lost when the session ends.

Figma links: Extract fileKey/nodeId, fetch via MCP if available, save screenshots to docs/arc/specs/assets/ Images: Describe in the spec, ask user to save to docs/arc/specs/assets/ manually External links/specs: Capture URL + description in the spec under "Reference Materials"

Reference Files

Read these when relevant (not all at once — load what the conversation needs):

1. references/question-loops.md — The one-question-at-a-time rules for Act 1
2. references/review-patterns.md — How to transform reviewer findings into questions
3. references/model-strategy.md — Which models for which agents
4. disciplines/dispatching-parallel-agents.md — Agent orchestration

"Would you like me to analyze this spec for missing user flows?"

If the user accepts:

1. Spawn the spec-flow-analyzer agent with the feature spec content
2. Present the gaps found
3. Offer to update the spec with any missing flows

Agent: agents/workflow/spec-flow-analyzer.md

This step is optional — skip if the user declines or wants to move straight to implementation.

• User's idea is fully understood through dialogue (not assumed)
• 2-3 approaches were considered, trade-offs explained
• UI requirements and external visual source are captured if UI is involved
• Spec presented in sections, each validated by user
• Expert review completed, findings discussed as questions
• Feature spec written; commit offered
• User chose next step