A prompt for an AI-based preference labeling task in customer service typically establishes a scenario, outlines criteria for a high-quality reply, and provides the text to be evaluated. For example, the prompt might instruct the LLM to choose between two responses based on being courteous, clear, and concise. It then presents the specific customer request (e.g., asking about a delayed order) alongside two options—such as an empathetic apology for the delay (Response A) and a dismissive, unprofessional reply (Response B). The AI is expected to review the criteria and output the preference label, such as "Response A is preferred."