Prompt Evaluation Harness Builder for Reusable AI Prompts
Create a structured evaluation harness for any reusable AI prompt, including test cases, expected outputs, scoring criteria, failure modes, regression checks, and prioritized improvement recommendations.
Published: Jun 12, 2026 · Updated: Jun 12, 2026
You are an expert prompt engineer and AI quality evaluator. Your task is to design a comprehensive evaluation harness for the prompt provided below. Context: - Prompt to evaluate: [Prompt to evaluate] - Prompt purpose: [Prompt purpose] - Target audience: [Target audience] - Intended AI model or tool: [Intended AI model or tool] - Expected output format: [Expected output format] - Brand voice or tone requirements: [Brand voice or tone requirements] - Safety, compliance, or policy constraints: [Safety, compliance, or policy constraints] - Known weaknesses or concerns: [Known weaknesses or concerns] - Success criteria: [Success criteria] - Definition of done: [Definition of done] Your task is to create a reusable prompt evaluation harness that can be used to test, score, and improve this prompt over time. Analyze the prompt for: Clarity and completeness Instruction-following Output consistency Accuracy and factual reliability Tone and audience fit Safety and compliance risks Edge-case handling Resistance to ambiguous, incomplete, or conflicting inputs Reusability across different scenarios Production readiness Create a structured evaluation harness with the following sections: 1. test_cases Create structured test cases covering: - Typical use cases - Edge cases - Ambiguous inputs - Incomplete inputs - Conflicting instructions - Unsafe or policy-sensitive requests - Low-quality user inputs - High-stakes scenarios, if applicable For each test case, include: - id - scenario - input - expected_output - evaluation_focus - likely_failure_modes - pass_criteria 2. scoring_rubric Create a quantitative and qualitative scoring rubric from 1 to 5 for each major evaluation dimension: - clarity - completeness - accuracy - instruction_following - output_format_consistency - tone_fit - safety - edge_case_handling - practical_usefulness - production_readiness For each score level, explain what a poor, acceptable, good, and excellent result looks like. 3. regression_checks - Define checks that should be repeated whenever the prompt is updated. Include: - baseline test cases that must always pass - output format checks - safety checks - tone checks - consistency checks - failure-mode checks - automation-friendly checks, where possible 4. improvement_recommendations Provide prioritized recommendations for improving the prompt. For each recommendation, include: - priority: high, medium, or low - issue - why_it_matters - suggested_fix - expected_impact 5. final_assessment Provide a concise final assessment of the prompt, including: - overall_score_out_of_100 - strongest_parts - weakest_parts - readiness_level: draft, usable, strong, or production-ready - next_best_action Constraints: - Output must be valid structured JSON. - Do not include markdown outside the JSON. - Test cases must be realistic and specific. - Recommendations must be practical and prioritized. - Do not invent sensitive facts or unsupported claims. - Make the harness reusable for future prompt versions. Return only the JSON object.
Variables to Replace
- Prompt to evaluate
- Prompt purpose
- Target audience
- Intended AI model or tool
- Expected output format
- Brand voice or tone requirements
- Safety, compliance, or policy constraints
- Known weaknesses or concerns
- Success criteria
- Definition of done
How to Use This Prompt
Paste the prompt you want to evaluate into the “Prompt to evaluate” field. Add the prompt’s purpose, target audience, preferred output format, tone requirements, known concerns, and success criteria. Run the prompt to generate a structured evaluation harness. Use the test cases and scoring rubric to compare prompt versions, detect regressions, and guide improvements.
Example Use Case
A SaaS team has a reusable customer support chatbot prompt and wants to improve response quality before deploying it. They paste the support prompt into this harness builder and generate test cases for common customer questions, refund requests, angry users, vague messages, and policy-sensitive scenarios. The scoring rubric helps the team compare different prompt versions, while the regression checks ensure future edits do not reduce safety, tone quality, or output consistency.