When you ask an LLM to “help with financial planning,” you might get a generic response that misses the nuance your situation requires. But what if you could transform that same LLM into a specialized Certified Financial Planner with 10 years of experience in debt management and retirement planning? That’s the power of role-based prompting, and it’s particularly valuable in financial services where precision and expertise matter.
The Problem with Generic AI Responses
Consider asking an AI: “I received a $15,000 bonus. How should I allocate it?”
A generic response might suggest:
- “You could save some, invest some, and pay off debt with the rest.”
Not wrong, but not helpful either. A financial advisor would ask about your interest rates, existing emergency fund, employer 401(k) match, and tax situation before giving specific advice.
Role-based prompting bridges this gap by giving the LLM a specific identity to inhabit - complete with expertise, methodology, and communication style.
What is Role-Based Prompting?
At its core, role-based prompting assigns a persona to your LLM. Think of it like casting an actor: you don’t just give them lines, you give them character background, motivation, and direction.
flowchart LR
subgraph Without Role
Q1[Query] --> G[Generic Response]
end
subgraph With Role
R[Role Definition] --> A[AI Persona]
Q2[Query] --> A
A --> S[Specialized Response]
end
classDef blueClass fill:#4A90E2,stroke:#333,stroke-width:2px,color:#fff
classDef orangeClass fill:#F39C12,stroke:#333,stroke-width:2px,color:#fff
class R blueClass
class A orangeClass
A Persona (or Role) defines how an agent should behave - its personality, tone, expertise, and perspective.
Why does this work? LLMs are trained on diverse data and have broad knowledge, but they need guidance to adopt a specific tone, style, or focus. Assigning a role directs the model’s response based on that defined identity.
Crafting Effective Role-Based Prompts
A well-structured role-based prompt typically includes these components:
| Component | Description | Example |
|---|---|---|
| Role | The persona to adopt | “You are a Certified Financial Planner (CFP)” |
| Task | The specific instruction | “Analyze this client’s budget and provide recommendations” |
| Output Format | How to structure the response | “Use bullet points with priority rankings” |
| Examples | Sample input/output pairs | “Finding: [insight]. Recommendation: [action]” |
| Context | Additional information needed | Client profile, financial data, constraints |
Not every prompt needs all components, but combining them produces more targeted results.
A Basic Example
1 | # Without role - generic response |
Progressive Refinement for Financial Personas
The real power comes from iteratively building your persona. Let me walk through how this works with a financial advisory scenario.
Level 1: Basic Role
1 | basic_system_prompt = "You are a helpful assistant." |
Response: Generic advice, no financial methodology, casual tone.
Level 2: Professional Role
1 | advisor_system_prompt = """ |
Response: More structured, takes on advisor tone, but lacks specificity.
Level 3: Specialized Expertise
1 | expert_system_prompt = """ |
Response: Uses established financial frameworks, provides methodologically sound advice.
Level 4: Communication Style
1 | styled_system_prompt = """ |
Response: Clear priorities, specific actions, explained reasoning - ready for client delivery.
The Transformation
Here’s what the final output looks like for a client allocating a $15,000 bonus:
1 | ### 1. Pay Off Credit Card Debt: $8,000 (Priority 1) |
Evaluating Persona Adherence
How do you know if your AI is actually following its assigned role? This is crucial for financial applications where consistency and accuracy matter.
Ground Truth Evaluation
Create a set of test scenarios with expected responses:
1 | test_cases = [ |
Consistency & Persona Adherence
Test whether the agent stays in character:
- Does a CFP persona refuse to give specific stock picks?
- Does it recommend consulting a tax professional for complex situations?
- Does it maintain professional boundaries when asked personal questions?
LLM-as-a-Judge
Use another LLM to evaluate responses:
1 | judge_prompt = """ |
Financial Domain Applications
Role-based prompting excels in financial services because the domain requires:
- Specialized knowledge: Tax rules, regulations, financial products
- Consistent methodology: Following established frameworks (50/30/20 rule, debt avalanche)
- Professional tone: Client-appropriate communication
- Clear disclaimers: When to recommend professional consultation
Example: Budget Analyst Persona
1 | budget_analyst = """ |
Example: Investment Advisor Persona
1 | investment_advisor = """ |
Key Principles for Financial Personas
After working with role-based prompting in financial contexts, these principles consistently improve results:
1. Be Specific About Credentials
“Certified Financial Planner” is better than “financial expert” because it implies specific training, ethics standards, and methodology.
2. Define Boundaries
Specify what the persona should NOT do:
1 | constraints = """ |
3. Include Methodology
Reference established frameworks:
1 | methodology = """ |
4. Specify Communication Style
1 | style = """ |
Connecting to Foundational Concepts
If you’re new to AI agents, check out my earlier post on From Chatbots to Agents which covers the fundamentals of how agents differ from simple chatbots.
Role-based prompting is the foundation for more sophisticated patterns we’ll explore in upcoming posts - including chain-of-thought reasoning for complex financial calculations and multi-step workflows for comprehensive financial planning.
Takeaways
Role-based prompting transforms generic AI into specialized experts by defining persona, expertise, and communication style
Progressive refinement works: Start with a basic role, add expertise, then layer in communication style
Evaluation matters: Use ground truth testing, consistency checks, and LLM-as-a-judge to verify persona adherence
Financial domains benefit significantly because they require specialized knowledge, consistent methodology, and professional communication
Define boundaries: Specify what the persona should NOT do, especially in regulated domains like finance
This is the first post in my Applied Agentic AI for Finance series. Next: Reasoning Chains for Financial Decisions where we’ll explore chain-of-thought prompting for complex financial analysis.
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