custom-personaslisted

# Custom Personas > The canonical 12 cover most decisions. They don't cover every domain. When you need a CFO for a budget brainstorm or a security engineer for threat modeling, design the persona — don't force a canonical to fit. This skill covers the design discipline for ad-hoc personas: when a custom is justified, how to write the persona prompt, how to invoke it inline (without shipping a new subagent file). ## Core principle **A custom persona is a tool, not a feature.** Design one when the canonical 12 demonstrably don't cover the domain. Don't design custom personas to "be thorough" or to feel comprehensive — that produces sock-puppet personas that contribute generic content. ## When a custom persona is justified A custom persona is justified when: 1. The domain has specialized knowledge that the canonical personas don't have (e.g. tax law, regulatory compliance, hardware reliability, biotech) 2. The decision affects a specific stakeholder group with a distinct perspective (e.g. enterprise procurement, customer success at scale, sales at a specific deal size) 3. The framing requires expertise the canonical personas wouldn't bring (e.g. economist for pricing strategy, behavioral psychologist for engagement design) 4. The brainstorm is industry-specific (e.g. healthcare, finance, defense, EdTech) A custom persona is NOT justified when: 1. The canonical personas would cover it adequately if you tightened their prompts 2. You're trying to "represent everyone" — t