Use BEFORE any creative/implementation work — new feature, component, behavior change, non-trivial design — to turn an idea into an approved design through one-question-at-a-time dialogue. Use when: "let's build", "I want to add", "how should we design", "new feature", vague/ambiguous scope. NOT for: trivial one-line changes, pure bug investigation (use a debugging protocol), or writing the step-by-step plan (that's /swe-skills:write-plans, the terminal state of this skill).
