Structured Brainstorming

Goal

Transform a raw idea into an approved design BEFORE specifying or implementing. Ideation phase between "I have a vague idea" and "here are the user stories".

Vague idea → BRAINSTORM → Validated design → /work:work-specify → /work:work-plan → /dev:dev-tdd

Iron Rule

IMPORTANT: Do NOT invoke an implementation skill, write code, scaffold a project, or take any implementation action until the design has been presented AND approved by the user.

Process

1. Explore the context

Before proposing anything:

• Read the relevant project files (architecture, existing code, CLAUDE.md)
• Check recent changes (git log --oneline -10)
• Identify existing technical constraints
• Understand the "why" behind the idea

2. Clarify through questioning

Ask clarification questions one at a time (not a block of 10 questions).

Stop questioning when there is enough context to propose alternatives.

3. Propose 2-3 approaches

For each approach, present:

### Approach A: [Descriptive name]

**Principle**: [1-2 sentences]

**Pros**:
- [Pro 1]
- [Pro 2]

**Cons**:
- [Con 1]
- [Con 2]

**Complexity**: [Low / Medium / High]

**Risks**:
- [Risk 1]

4. Challenge the approaches

After presenting the alternatives:

• Apply YAGNI: "Do we really need X?"
• Look for the simplest solution that works
• Identify pieces that can be deferred (P2/P3)
• Check that a solution does not already exist in the codebase or dependencies

5. Converge on a design

Once the user has chosen a direction:

• Decompose the system into units with a single clear goal
• Define the interfaces between units
• Make sure each unit can be tested independently
• Present section by section, asking for validation at each step

6. Document the design

Write the design in a file:

docs/designs/YYYY-MM-DD-[topic]-design.md

Format:

# Design: [Title]

**Date**: YYYY-MM-DD
**Status**: Approved / Under discussion

## Context
[Why this design is needed]

## Decision
[Chosen approach and why]

## Alternatives considered
[Rejected approaches and why]

## Detailed design
[Breakdown into components, interfaces, flows]

## Identified risks
[Risks and mitigations]

## Out of scope
[What is NOT included in this design]

7. Self-review

Before presenting the final design, check:

• [ ] No placeholders ("TBD", "to be defined", "TODO")
• [ ] No contradictions between sections
• [ ] No ambiguities (each term has a single interpretation)
• [ ] YAGNI applied (no speculative features)
• [ ] Each component is testable independently
• [ ] Interfaces between components are explicit

8. Handoff

Once the design is approved, propose:

Design approved. Next steps:
1. `/work:work-specify` — Transform this design into testable user stories
2. `/work:work-plan` — Plan the technical implementation

Design principles

• Decompose into units that each have a clear goal
• Explicit interfaces between units
• Independently testable: each unit can be tested alone
• YAGNI: no speculative features, no premature generalization
• Simplicity: the simplest solution that works is the best
• Reversibility: prefer decisions that are easy to change

Expected output

## Brainstorm: [Title]

### Context
[What we have understood about the need]

### Approaches explored
| Approach | Strengths | Weaknesses | Complexity |
|----------|--------|------------|------------|
| A: [...] | [...] | [...] | Low |
| B: [...] | [...] | [...] | Medium |
| C: [...] | [...] | [...] | High |

### Decision
**Chosen approach**: [X]
**Reason**: [Why this approach]

### Design
[Breakdown, interfaces, flows]

### Next steps
1. `/work:work-specify` for the user stories
2. `/work:work-plan` for the technical plan

Related agents

Rules

• ALWAYS explore the context before proposing
• ALWAYS propose at least 2 approaches with trade-offs
• NEVER implement before explicit approval of the design
• Ask clarification questions ONE AT A TIME
• Apply YAGNI systematically
• Document rejected alternatives (not just the chosen one)