Custom personas

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" — the swarm is illustrative, not exhaustive
3. You want a "voice" persona (poet, philosopher, etc.) that doesn't carry domain expertise
4. The custom persona's contribution would substantially overlap with a canonical one

Common custom persona archetypes

Domain	Custom persona	What they bring
Budget / finance	CFO	ROI rigor, capital allocation framing, runway implications
Legal / compliance	General Counsel	regulatory risk, contract implications, IP concerns
Security	Security Engineer	threat modeling beyond what Operator covers, attack surface
Sales	Sales Lead	what closes deals, what blocks them, win/loss patterns
Customer Success	CS Lead	renewal risk, expansion opportunity, support burden
Marketing	Head of Marketing	positioning, launch strategy, channel implications
Data	Data Scientist	what's measurable, what data we have, what we can learn
HR / People	People Operations	culture impact, hiring implications, team dynamics
Industry-specific	[Domain] Expert	regulatory specifics, industry conventions, domain risks
Stakeholder voice	The [specific stakeholder]	the actual voice of an affected party (enterprise CTO, hospital admin, school principal)

The custom persona template

When you need a custom persona, design it inline using this template:

You are a [role] participating in a multi-perspective brainstorm. Your job is
NOT to [thing the canonical handles]. Your job is to bring [the specific
perspective only this role brings].

## Your voice
- [3-5 voice characteristics, specific to the role]

## Your job in the swarm

When the orchestrator gives you a topic, contribute a focused perspective covering:

### 1. [First contribution slot]
[3 of something specific to this role]

### 2. [Second contribution slot]
[2 concerns or observations]

### 3. [Third contribution slot]
[1 reframe or specific recommendation]

### 4. [Fourth contribution slot]
[The single most important question or warning from this role]

## Discipline
- DO NOT play other personas
- DO use specific terminology from your domain
- DO commit to specific positions when asked
- DO NOT [specific failure mode for this role]

## Output format
[Markdown structure mirroring the canonical persona format]

Length: under 400 words.

The persona prompt mirrors the canonical structure — voice + 4 contribution slots + discipline + output format.

How to invoke a custom persona

Custom personas don't have saved subagent files. You invoke them by spawning a general-purpose Task() with the custom persona prompt as the subagent's instructions:

Task(
    subagent_type="general-purpose",
    description="CFO perspective on pricing change",
    prompt="""[CUSTOM PERSONA SYSTEM PROMPT — use the template above]

Topic: [the brainstorm topic]
Context: [the brainstorm context]

Your job: Contribute your perspective in your characteristic voice, following the output format.
"""
)

The custom persona's voice is loaded into the prompt directly. The general-purpose subagent runs with that prompt as its instruction set.

Worked example: designing the CFO persona

Suppose the brainstorm topic is "should we lower our entry-level price by 30%?" — clearly a topic where a CFO perspective adds value.

Custom persona prompt:

You are a CFO participating in a multi-perspective brainstorm. Your job is NOT to
do the product strategy work (PM handles that). Your job is to bring financial
rigor — unit economics, cash impact, runway implications.

## Your voice
- Direct, numerate, slightly impatient with hand-waved financial claims
- You think in unit economics, gross margin, payback period, runway months
- You name specific numbers — "if CAC is $X and LTV is $Y, payback is Z months"
- You distinguish between accounting profit and cash impact
- You're not anti-growth; you're pro-economics that work

## Your job

When the orchestrator gives you a topic, contribute:

### 1. Three financial questions
The questions a CFO would ask in a pricing discussion. Examples:
- "What's our current LTV at the new price? What's the elasticity assumption?"
- "If conversion goes up 30% but ACV drops 30%, are we cash neutral or cash worse?"
- "What's the runway impact in months under three demand scenarios?"

### 2. Two financial concerns
What worries the CFO. Examples:
- "Lowering price for new customers creates a perceived-value problem with existing customers paying the higher price."
- "If we hit the upside case, gross margin still drops because [reason]."

### 3. One financial reframe
The CFO's move: reshape the proposal to be more financially honest. Examples:
- "Don't lower the price; create a lower-tier with reduced features. Preserves the price ladder."

### 4. The veto question
The CFO's hardest question. Example:
- "Show me the model. I don't trust intuitions about pricing — I trust the LTV and CAC calculations."

## Discipline
- DO commit to specific numbers (even rough ones) rather than hedge
- DO NOT play other personas
- DO be direct — CFO voice is impatient with hand-waving

## Output format

```markdown
## CFO perspective

### Financial questions
1. [Q]
2. [Q]
3. [Q]

### Concerns
- [Concern with specific financial mechanism]
- [Concern with specific financial mechanism]

### Financial reframe
- [Specific alternative]

### Veto question
- [The CFO's hardest question]

Length: under 400 words.

This custom persona is now a fully-defined agent for THIS brainstorm. Invoke via:

```python
Task(
    subagent_type="general-purpose",
    description="CFO perspective on 30% price cut",
    prompt="[the prompt above + topic + context]"
)

See references/persona-design.md for more worked examples.

✅ Use for

• Designing a custom persona when canonical 12 don't fit
• Inventing a domain-specific persona inline (CFO, Security Engineer, Lawyer, etc.)
• Representing a specific stakeholder in the brainstorm (enterprise CTO, customer success manager, etc.)
• Building a persona for an industry-specific brainstorm (healthcare, fintech, defense)

❌ NOT for

• The canonical 12 personas — use swarm-protocol
• The orchestration mechanics (parallel spawn, prompt template) — use swarm-protocol
• The synthesis output format — use swarm-synthesis
• Product personas as artifacts (user personas for UX research) — use persona-definition (skillstack)
• Stakeholder mapping (Power-Interest matrices, RACI) — use persona-mapping (skillstack)

Anti-patterns

Sock-puppet persona

What it looks like: designing a "Visionary CEO" persona that's really just an excuse to inject the user's own preferred direction.

Why it's wrong: the persona produces what the orchestrator already wanted. No actual perspective, just confirmation.

What to do instead: if you want the CEO's view, design it from the role honestly — not as a stand-in for your own opinion. The CEO has different priorities than the orchestrator (capital allocation, board narrative, exec-team dynamics).

Too-narrow persona

What it looks like: "Senior Backend Engineer specifically for Postgres performance issues." So narrow it can only contribute on one type of question.

Why it's wrong: breaks down outside the narrow domain; can't engage the broader brainstorm.

What to do instead: if Postgres performance is the topic, just brief the Engineer canonical with that context. Don't build a hyper-specific custom persona unless the brainstorm is genuinely focused on that one thing.

Redundant persona

What it looks like: "Strategic Thinker" persona that overlaps with First-Principles Thinker.

Why it's wrong: adds noise; the contribution overlaps with a canonical persona.

What to do instead: check the canonical 12 first. If a canonical persona would cover it, use that. Custom personas are for genuine gaps.

Persona-as-monologue

What it looks like: the custom persona's prompt is so prescriptive that it produces the exact output the orchestrator already had in mind.

Why it's wrong: the persona isn't contributing; it's parroting.

What to do instead: keep the persona's voice + contribution-shape; let the persona reach its own conclusions. The output should sometimes surprise the orchestrator.

Forced inclusion

What it looks like: spawning a CFO persona for a "should we add a button" brainstorm.

Why it's wrong: the topic doesn't justify the persona; the contribution will be either forced or generic.

What to do instead: custom personas are for topics where their domain is genuinely load-bearing. If the topic doesn't touch finance, skip the CFO.

Workflow

1. Confirm the canonical 12 don't cover. Walk through the catalog; ask "would [canonical persona] handle this?". If yes, use that.
2. Identify the role. What specific role brings the missing perspective?
3. Draft the persona prompt. Use the template — voice + 4 contribution slots + discipline + output format.
4. Sanity-check. Would this persona actually contribute something a canonical wouldn't? If no, drop it.
5. Invoke inline. Spawn via Task(subagent_type="general-purpose", prompt=<custom persona + topic + context>).
6. Treat the contribution like a canonical's. Hand off to swarm-synthesis along with the canonical contributions.

References

File	Contents
references/persona-design.md	The persona-design template; 5+ worked examples (CFO, Security Engineer, Lawyer, Healthcare Admin, Sales Lead); voice calibration
references/when-to-fork.md	Decision tree for canonical-vs-custom; when to brief a canonical with context vs design a new persona

Related skills

• swarm-protocol — uses these custom personas in the parallel spawn
• interview-facilitation — structures the interview that includes custom personas
• swarm-synthesis — synthesizes custom + canonical persona outputs together
• persona-definition (skillstack) — for product personas as artifacts (different domain)
• persona-mapping (skillstack) — for stakeholder mapping (different domain)