The Prompt Builder Best Practices Guide emphasizes including a role instruction in prompts to set tone and communication style. The document explains: “Role-playing instructions (e.g., ‘You are an empathetic customer support agent’) are a best practice for ensuring the LLM adopts the desired persona, tone, and style in responses.”

Option A directly reflects this principle by instructing the LLM to role-play as a character, resulting in empathetic, customer-centric responses.

Option B (listing keywords) provides no tone or intent guidance.

Option C (including full interaction history) risks token overload and redundancy, which can degrade prompt performance.

Thus, Option A aligns with Salesforce’s prompt design best practices for tone and empathy.

References (AgentForce Documents / Study Guide):

Salesforce Prompt Builder Design Guide: “Using Role Instructions for Empathy and Tone”

AgentForce Prompt Engineering Handbook: “Persona and Context in Prompts”

AgentForce Study Guide: “Creating Effective Prompts for Customer-Facing Use Cases”