define

name	define
description	Phase 2 of design thinking. Synthesize understanding into a precise problem definition and spec. Produces a spec with explicit success/failure criteria. Input: context brief from /understand. Invoke after Understand, or when Ideate reveals the spec is too vague.

Define — Phase 2 of Design Thinking

Using define to synthesize understanding into a precise spec with verifiable criteria.

Goal

Produce docs/dt/spec.md.

Primary Input

Read docs/dt/context-brief.md before doing anything else.

What the Spec Contains

• Problem statement — refined from the context brief; the one-sentence core of what must be solved.
• Success criteria — explicit, verifiable conditions that indicate the solution works. Each criterion must be checkable by the Test phase without ambiguity.
• Failure criteria — conditions that indicate the solution is wrong, even if it appears to work. What would make a "passing" solution actually unacceptable.
• Invariants — things that must always remain true regardless of what approach is chosen.
• Scope — what is in this cycle and what is explicitly out.
• Open decisions — explicit choices deferred to Ideate, listed with the known tradeoffs.

What Does NOT Belong in the Spec

• How to solve it.
• Implementation approaches or technology choices.
• Task breakdowns.
• Code or pseudocode.

The spec defines the target, not the path.

Procedure

1. Read the context brief. Internalize the problem statement, constraints, and open questions.
2. Identify gaps. Are there open questions from the context brief that block writing verifiable criteria? Ask Alex to resolve them, ONE question at a time.
3. Write the spec to docs/dt/spec.md. Use the frontmatter:

   ---
   date: YYYY-MM-DD
   phase: define
   status: complete
   ---
   

4. Self-review. Check: Is any success criterion not verifiable? Does any criterion contradict another? Are all constraints from the context brief reflected? Fix before committing.
5. Commit.

   docs(dt): complete define phase — <brief description>
   

6. Hand off.

Handoff

Phase complete: Define
Artifact: docs/dt/spec.md

Next: open a new agent session, invoke /ideate, read docs/dt/spec.md first.

Back-transitions: if spec reveals the problem was not understood → /understand
Skip forward: if you already have a clear plan → /ideate