brainstorming - SKILL.md Agent Skill

name: brainstorming description: "You MUST use this before any creative work - creating features, building components, adding functionality, modifying behavior, or evaluating a plan/design. Relentlessly explores user intent, requirements, trade-offs, and decision branches before implementation."

Brainstorming Ideas Into Designs

Help turn ideas into fully formed designs and specs through natural collaborative dialogue.

Start by understanding the current project context, then interview the user one decision at a time until the design is concrete. Walk the design tree branch-by-branch, resolve dependencies between choices, and provide your recommended answer with reasoning for every question. Once you understand what you're building, present the design and get user approval.

Do NOT invoke any implementation skill, write any code, scaffold any project, or take any implementation action until you have presented a design and the user has approved it. This applies to EVERY project regardless of perceived simplicity.

Anti-Pattern: "This Is Too Simple To Need A Design"

Every project goes through this process. A todo list, a single-function utility, a config change — all of them. "Simple" projects are where unexamined assumptions cause the most wasted work. The design can be short (a few sentences for truly simple projects), but you MUST present it and get approval.

Checklist

You MUST create a task for each of these items and complete them in order:

Explore project context — check files, docs, recent commits
Interview branch-by-branch — ask one question at a time, include your recommended answer, and resolve purpose/constraints/success criteria/decision dependencies
Propose 2-3 approaches — with trade-offs and your recommendation
Present design — in sections scaled to their complexity, get user approval after each section
Write design doc — save to docs/pi/specs/YYYY-MM-DD-<topic>-design.md and commit
Spec self-review — quick inline check for placeholders, contradictions, ambiguity, scope (see below)
Spec document reviewer — dispatch a reviewer subagent with ./spec-document-reviewer-prompt.md; fix blocking issues
User reviews written spec — ask user to review the spec file before proceeding
Transition to implementation — invoke writing-plans skill to create implementation plan

Process Flow

digraph brainstorming {
    "Explore project context" [shape=box];
    "Interview branch-by-branch" [shape=box];
    "Propose 2-3 approaches" [shape=box];
    "Present design sections" [shape=box];
    "User approves design?" [shape=diamond];
    "Write design doc" [shape=box];
    "Spec self-review\n(fix inline)" [shape=box];
    "Dispatch spec reviewer" [shape=box];
    "Reviewer finds blocking issues?" [shape=diamond];
    "User reviews spec?" [shape=diamond];
    "Invoke writing-plans skill" [shape=doublecircle];

    "Explore project context" -> "Interview branch-by-branch";
    "Interview branch-by-branch" -> "Propose 2-3 approaches";
    "Propose 2-3 approaches" -> "Present design sections";
    "Present design sections" -> "User approves design?";
    "User approves design?" -> "Present design sections" [label="no, revise"];
    "User approves design?" -> "Write design doc" [label="yes"];
    "Write design doc" -> "Spec self-review\n(fix inline)";
    "Spec self-review\n(fix inline)" -> "Dispatch spec reviewer";
    "Dispatch spec reviewer" -> "Reviewer finds blocking issues?";
    "Reviewer finds blocking issues?" -> "Write design doc" [label="yes, fix"];
    "Reviewer finds blocking issues?" -> "User reviews spec?" [label="no"];
    "User reviews spec?" -> "Write design doc" [label="changes requested"];
    "User reviews spec?" -> "Invoke writing-plans skill" [label="approved"];
}

The terminal state is invoking writing-plans. Do NOT invoke any implementation skill. The ONLY skill you invoke after brainstorming is writing-plans.

The Process

Understanding the idea:

Check out the current project state first (files, docs, recent commits)
Before asking detailed questions, assess scope: if the request describes multiple independent subsystems (e.g., "build a platform with chat, file storage, billing, and analytics"), flag this immediately. Don't spend questions refining details of a project that needs to be decomposed first.
If the project is too large for a single spec, help the user decompose into sub-projects: what are the independent pieces, how do they relate, what order should they be built? Then brainstorm the first sub-project through the normal design flow. Each sub-project gets its own spec → plan → implementation cycle.
For appropriately-scoped projects, interview relentlessly until the design is concrete
Walk down each branch of the design tree, resolving dependencies between decisions one-by-one
Ask exactly one question at a time; if a topic needs more exploration, split it into multiple questions
Prefer multiple choice questions when possible. Use the user_select tool whenever the answers can be expressed as concrete choices
For each question, provide your recommended answer and the reason for that recommendation
If a question can be answered by exploring the codebase, inspect the relevant files instead of asking the user
Focus on understanding: purpose, constraints, success criteria, trade-offs, and open decision branches

Exploring approaches:

Propose 2-3 different approaches with trade-offs
Present options conversationally with your recommendation and reasoning
Lead with your recommended option and explain why

Presenting the design:

Once you believe you understand what you're building, present the design
Scale each section to its complexity: a few sentences if straightforward, up to 200-300 words if nuanced
Ask after each section whether it looks right so far
Cover: architecture, components, data flow, error handling, testing
Be ready to go back and clarify if something doesn't make sense

Design for isolation and clarity:

Break the system into smaller units that each have one clear purpose, communicate through well-defined interfaces, and can be understood and tested independently
For each unit, you should be able to answer: what does it do, how do you use it, and what does it depend on?
Can someone understand what a unit does without reading its internals? Can you change the internals without breaking consumers? If not, the boundaries need work.
Smaller, well-bounded units are also easier for you to work with - you reason better about code you can hold in context at once, and your edits are more reliable when files are focused. When a file grows large, that's often a signal that it's doing too much.

Working in existing codebases:

Explore the current structure before proposing changes. Follow existing patterns.
Where existing code has problems that affect the work (e.g., a file that's grown too large, unclear boundaries, tangled responsibilities), include targeted improvements as part of the design - the way a good developer improves code they're working in.
Don't propose unrelated refactoring. Stay focused on what serves the current goal.

After the Design

Documentation:

Write the validated design (spec) to docs/pi/specs/YYYY-MM-DD-<topic>-design.md
- (User preferences for spec location override this default)
Commit the design document to git

Spec Self-Review: After writing the spec document, look at it with fresh eyes:

Placeholder scan: Any "TBD", "TODO", incomplete sections, or vague requirements? Fix them.
Internal consistency: Do any sections contradict each other? Does the architecture match the feature descriptions?
Scope check: Is this focused enough for a single implementation plan, or does it need decomposition?
Ambiguity check: Could any requirement be interpreted two different ways? If so, pick one and make it explicit.

Fix any issues inline, then run the reviewer pass.

Spec Document Reviewer: After self-review passes, dispatch a fresh-context reviewer subagent using ./spec-document-reviewer-prompt.md (resolve relative to this SKILL.md):

subagent({ agent: "reviewer", task: <filled template>, context: "fresh" })

Fill [SPEC_FILE_PATH] with the written spec path. If the reviewer returns Issues Found, fix every blocking issue and repeat self-review plus reviewer pass. Treat recommendations as advisory; apply them only when they materially improve implementation planning.

User Review Gate: After the reviewer pass is approved, ask the user to review the written spec before proceeding:

"Spec written and committed to <path>. Please review it and let me know if you want to make any changes before we start writing out the implementation plan."

Wait for the user's response. If they request changes, make them and re-run the spec review loop. Only proceed once the user approves.

Implementation:

Invoke the writing-plans skill to create a detailed implementation plan
Do NOT invoke any other implementation skill. writing-plans is the next implementation step.

Related Skills

writing-plans - Next implementation workflow after the design/spec is approved.
verification-before-completion - Terminal gate for this workflow. Before claiming the design, spec, reviewer pass, or handoff is complete, run fresh verification and report evidence.

Key Principles

One question at a time - Don't overwhelm with multiple questions
Recommended answer every time - Make your judgment explicit so the user can accept, reject, or correct it
Multiple choice preferred - Easier to answer than open-ended when possible
YAGNI ruthlessly - Remove unnecessary features from all designs
Explore alternatives - Always propose 2-3 approaches before settling
Incremental validation - Present design, get approval before moving on
Be flexible - Go back and clarify when something doesn't make sense