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Evaluating Llms

  • 67 installs
  • 426 repo stars
  • Updated December 11, 2025
  • ancoleman/ai-design-components

evaluating-llms is a Claude skill that evaluates LLM and RAG systems using automated metrics, LLM-as-judge patterns, and benchmarks.

About

This skill evaluates LLM systems using automated metrics, LLM-as-judge patterns, and standardized benchmarks. A developer uses it when testing prompt quality, validating RAG pipelines, measuring hallucinations or bias, or comparing models before deployment. It provides decision frameworks by task type and cost, plus a layered production evaluation strategy that fits into CI/CD.

  • Evaluation approach selection by task type, volume, and cost
  • Automated metrics, LLM-as-judge, and RAGAS RAG evaluation patterns
  • Layered production strategy with CI/CD integration

Evaluating Llms by the numbers

  • 67 all-time installs (skills.sh)
  • Ranked #5,935 of 16,546 AI & Agent Building skills by installs in the Skillselion catalog
  • Data as of Aug 5, 2026 (Skillselion catalog sync)
At a glance

evaluating-llms capabilities & compatibility

Capabilities
llm evaluation · rag evaluation · model comparison · hallucination detection
Works with
openai · anthropic
Use cases
testing · research
From the docs

What evaluating-llms says it does

Evaluate Large Language Model (LLM) systems using automated metrics, LLM-as-judge patterns, and standardized benchmarks to ensure production quality and safety.
SKILL.md
Faithfulness** (Target: > 0.8) - **MOST CRITICAL
SKILL.md
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Installs67
repo stars426
Last updatedDecember 11, 2025
Repositoryancoleman/ai-design-components

What it does

Evaluating LLM and RAG systems with automated metrics, LLM-as-judge, and benchmarks before production deployment.

Who is it for?

Testing prompt quality, validating RAG pipelines, and comparing models before production.

Skip if: Non-LLM software with no model outputs to evaluate.

When should I use this skill?

Testing prompts, validating RAG quality, measuring hallucinations/bias, or comparing models.

What you get

An evaluation strategy with automated metrics, LLM-as-judge, and RAGAS scores gating production quality.

  • Evaluation strategy
  • Metric suite
  • RAGAS scores

By the numbers

  • RAGAS faithfulness target > 0.8
  • 3-layer production evaluation strategy (automated/LLM-judge/human)

Files

SKILL.mdMarkdownGitHub ↗

LLM Evaluation

Evaluate Large Language Model (LLM) systems using automated metrics, LLM-as-judge patterns, and standardized benchmarks to ensure production quality and safety.

When to Use This Skill

Apply this skill when:

  • Testing individual prompts for correctness and formatting
  • Validating RAG (Retrieval-Augmented Generation) pipeline quality
  • Measuring hallucinations, bias, or toxicity in LLM outputs
  • Comparing different models or prompt configurations (A/B testing)
  • Running benchmark tests (MMLU, HumanEval) to assess model capabilities
  • Setting up production monitoring for LLM applications
  • Integrating LLM quality checks into CI/CD pipelines

Common triggers:

  • "How do I test if my RAG system is working correctly?"
  • "How can I measure hallucinations in LLM outputs?"
  • "What metrics should I use to evaluate generation quality?"
  • "How do I compare GPT-4 vs Claude for my use case?"
  • "How do I detect bias in LLM responses?"

Evaluation Strategy Selection

Decision Framework: Which Evaluation Approach?

By Task Type:

Task TypePrimary ApproachMetricsTools
Classification (sentiment, intent)Automated metricsAccuracy, Precision, Recall, F1scikit-learn
Generation (summaries, creative text)LLM-as-judge + automatedBLEU, ROUGE, BERTScore, Quality rubricGPT-4/Claude for judging
Question AnsweringExact match + semantic similarityEM, F1, Cosine similarityCustom evaluators
RAG SystemsRAGAS frameworkFaithfulness, Answer/Context relevanceRAGAS library
Code GenerationUnit tests + executionPass@K, Test pass rateHumanEval, pytest
Multi-step AgentsTask completion + tool accuracySuccess rate, EfficiencyCustom evaluators

By Volume and Cost:

SamplesSpeedCostRecommended Approach
1,000+Immediate$0Automated metrics (regex, JSON validation)
100-1,000Minutes$0.01-0.10 eachLLM-as-judge (GPT-4, Claude)
< 100Hours$1-10 eachHuman evaluation (pairwise comparison)

Layered Approach (Recommended for Production): 1. Layer 1: Automated metrics for all outputs (fast, cheap) 2. Layer 2: LLM-as-judge for 10% sample (nuanced quality) 3. Layer 3: Human review for 1% edge cases (validation)

Core Evaluation Patterns

Unit Evaluation (Individual Prompts)

Test single prompt-response pairs for correctness.

Methods:

  • Exact Match: Response exactly matches expected output
  • Regex Matching: Response follows expected pattern
  • JSON Schema Validation: Structured output validation
  • Keyword Presence: Required terms appear in response
  • LLM-as-Judge: Binary pass/fail using evaluation prompt

Example Use Cases:

  • Email classification (spam/not spam)
  • Entity extraction (dates, names, locations)
  • JSON output formatting validation
  • Sentiment analysis (positive/negative/neutral)

Quick Start (Python):

import pytest
from openai import OpenAI

client = OpenAI()

def classify_sentiment(text: str) -> str:
    response = client.chat.completions.create(
        model="gpt-3.5-turbo",
        messages=[
            {"role": "system", "content": "Classify sentiment as positive, negative, or neutral. Return only the label."},
            {"role": "user", "content": text}
        ],
        temperature=0
    )
    return response.choices[0].message.content.strip().lower()

def test_positive_sentiment():
    result = classify_sentiment("I love this product!")
    assert result == "positive"

For complete unit evaluation examples, see examples/python/unit_evaluation.py and examples/typescript/unit-evaluation.ts.

RAG (Retrieval-Augmented Generation) Evaluation

Evaluate RAG systems using RAGAS framework metrics.

Critical Metrics (Priority Order):

1. Faithfulness (Target: > 0.8) - MOST CRITICAL

  • Measures: Is the answer grounded in retrieved context?
  • Prevents hallucinations
  • If failing: Adjust prompt to emphasize grounding, require citations

2. Answer Relevance (Target: > 0.7)

  • Measures: How well does the answer address the query?
  • If failing: Improve prompt instructions, add few-shot examples

3. Context Relevance (Target: > 0.7)

  • Measures: Are retrieved chunks relevant to the query?
  • If failing: Improve retrieval (better embeddings, hybrid search)

4. Context Precision (Target: > 0.5)

  • Measures: Are relevant chunks ranked higher than irrelevant?
  • If failing: Add re-ranking step to retrieval pipeline

5. Context Recall (Target: > 0.8)

  • Measures: Are all relevant chunks retrieved?
  • If failing: Increase retrieval count, improve chunking strategy

Quick Start (Python with RAGAS):

from ragas import evaluate
from ragas.metrics import faithfulness, answer_relevancy, context_relevancy
from datasets import Dataset

data = {
    "question": ["What is the capital of France?"],
    "answer": ["The capital of France is Paris."],
    "contexts": [["Paris is the capital of France."]],
    "ground_truth": ["Paris"]
}

dataset = Dataset.from_dict(data)
results = evaluate(dataset, metrics=[faithfulness, answer_relevancy, context_relevancy])
print(f"Faithfulness: {results['faithfulness']:.2f}")

For comprehensive RAG evaluation patterns, see references/rag-evaluation.md and examples/python/ragas_example.py.

LLM-as-Judge Evaluation

Use powerful LLMs (GPT-4, Claude Opus) to evaluate other LLM outputs.

When to Use:

  • Generation quality assessment (summaries, creative writing)
  • Nuanced evaluation criteria (tone, clarity, helpfulness)
  • Custom rubrics for domain-specific tasks
  • Medium-volume evaluation (100-1,000 samples)

Correlation with Human Judgment: 0.75-0.85 for well-designed rubrics

Best Practices:

  • Use clear, specific rubrics (1-5 scale with detailed criteria)
  • Include few-shot examples in evaluation prompt
  • Average multiple evaluations to reduce variance
  • Be aware of biases (position bias, verbosity bias, self-preference)

Quick Start (Python):

from openai import OpenAI

client = OpenAI()

def evaluate_quality(prompt: str, response: str) -> tuple[int, str]:
    """Returns (score 1-5, reasoning)"""
    eval_prompt = f"""
Rate the following LLM response on relevance and helpfulness.

USER PROMPT: {prompt}
LLM RESPONSE: {response}

Provide:
Score: [1-5, where 5 is best]
Reasoning: [1-2 sentences]
"""
    result = client.chat.completions.create(
        model="gpt-4",
        messages=[{"role": "user", "content": eval_prompt}],
        temperature=0.3
    )
    content = result.choices[0].message.content
    lines = content.strip().split('\n')
    score = int(lines[0].split(':')[1].strip())
    reasoning = lines[1].split(':', 1)[1].strip()
    return score, reasoning

For detailed LLM-as-judge patterns and prompt templates, see references/llm-as-judge.md and examples/python/llm_as_judge.py.

Safety and Alignment Evaluation

Measure hallucinations, bias, and toxicity in LLM outputs.

Hallucination Detection

Methods:

1. Faithfulness to Context (RAG):

  • Use RAGAS faithfulness metric
  • LLM checks if claims are supported by context
  • Score: Supported claims / Total claims

2. Factual Accuracy (Closed-Book):

  • LLM-as-judge with access to reliable sources
  • Fact-checking APIs (Google Fact Check)
  • Entity-level verification (dates, names, statistics)

3. Self-Consistency:

  • Generate multiple responses to same question
  • Measure agreement between responses
  • Low consistency suggests hallucination
Bias Evaluation

Types of Bias:

  • Gender bias (stereotypical associations)
  • Racial/ethnic bias (discriminatory outputs)
  • Cultural bias (Western-centric assumptions)
  • Age/disability bias (ableist or ageist language)

Evaluation Methods:

1. Stereotype Tests:

  • BBQ (Bias Benchmark for QA): 58,000 question-answer pairs
  • BOLD (Bias in Open-Ended Language Generation)

2. Counterfactual Evaluation:

  • Generate responses with demographic swaps
  • Example: "Dr. Smith (he/she) recommended..." → compare outputs
  • Measure consistency across variations
Toxicity Detection

Tools:

  • Perspective API (Google): Toxicity, threat, insult scores
  • Detoxify (HuggingFace): Open-source toxicity classifier
  • OpenAI Moderation API: Hate, harassment, violence detection

For comprehensive safety evaluation patterns, see references/safety-evaluation.md.

Benchmark Testing

Assess model capabilities using standardized benchmarks.

Standard Benchmarks:

BenchmarkCoverageFormatDifficultyUse Case
MMLU57 subjects (STEM, humanities)Multiple choiceHigh school - professionalGeneral intelligence
HellaSwagSentence completionMultiple choiceCommon senseReasoning validation
GPQAPhD-level scienceMultiple choiceVery high (expert-level)Frontier model testing
HumanEval164 Python problemsCode generationMediumCode capability
MATH12,500 competition problemsMath solvingHigh school competitionsMath reasoning

Domain-Specific Benchmarks:

  • Medical: MedQA (USMLE), PubMedQA
  • Legal: LegalBench
  • Finance: FinQA, ConvFinQA

When to Use Benchmarks:

  • Comparing multiple models (GPT-4 vs Claude vs Llama)
  • Model selection for specific domains
  • Baseline capability assessment
  • Academic research and publication

Quick Start (lm-evaluation-harness):

pip install lm-eval

# Evaluate GPT-4 on MMLU
lm_eval --model openai-chat --model_args model=gpt-4 --tasks mmlu --num_fewshot 5

For detailed benchmark testing patterns, see references/benchmarks.md and scripts/benchmark_runner.py.

Production Evaluation

Monitor and optimize LLM quality in production environments.

A/B Testing

Compare two LLM configurations:

  • Variant A: GPT-4 (expensive, high quality)
  • Variant B: Claude Sonnet (cheaper, fast)

Metrics:

  • User satisfaction scores (thumbs up/down)
  • Task completion rates
  • Response time and latency
  • Cost per successful interaction
Online Evaluation

Real-time quality monitoring:

  • Response Quality: LLM-as-judge scoring every Nth response
  • User Feedback: Explicit ratings, thumbs up/down
  • Business Metrics: Conversion rates, support ticket resolution
  • Cost Tracking: Tokens used, inference costs
Human-in-the-Loop

Sample-based human evaluation:

  • Random Sampling: Evaluate 10% of responses
  • Confidence-Based: Evaluate low-confidence outputs
  • Error-Triggered: Flag suspicious responses for review

For production evaluation patterns and monitoring strategies, see references/production-evaluation.md.

Classification Task Evaluation

For tasks with discrete outputs (sentiment, intent, category).

Metrics:

  • Accuracy: Correct predictions / Total predictions
  • Precision: True positives / (True positives + False positives)
  • Recall: True positives / (True positives + False negatives)
  • F1 Score: Harmonic mean of precision and recall
  • Confusion Matrix: Detailed breakdown of prediction errors

Quick Start (Python):

from sklearn.metrics import accuracy_score, precision_recall_fscore_support

y_true = ["positive", "negative", "neutral", "positive", "negative"]
y_pred = ["positive", "negative", "neutral", "neutral", "negative"]

accuracy = accuracy_score(y_true, y_pred)
precision, recall, f1, _ = precision_recall_fscore_support(y_true, y_pred, average='weighted')

print(f"Accuracy: {accuracy:.2f}")
print(f"Precision: {precision:.2f}")
print(f"Recall: {recall:.2f}")
print(f"F1 Score: {f1:.2f}")

For complete classification evaluation examples, see examples/python/classification_metrics.py.

Generation Task Evaluation

For open-ended text generation (summaries, creative writing, responses).

Automated Metrics (Use with Caution):

  • BLEU: N-gram overlap with reference text (0-1 score)
  • ROUGE: Recall-oriented overlap (ROUGE-1, ROUGE-L)
  • METEOR: Semantic similarity with stemming
  • BERTScore: Contextual embedding similarity (0-1 score)

Limitation: Automated metrics correlate weakly with human judgment for creative/subjective generation.

Recommended Approach: 1. Automated metrics: Fast feedback for objective aspects (length, format) 2. LLM-as-judge: Nuanced quality assessment (relevance, coherence, helpfulness) 3. Human evaluation: Final validation for subjective criteria (preference, creativity)

For detailed generation evaluation patterns, see references/evaluation-types.md.

Quick Reference Tables

Evaluation Framework Selection

If Task Is...Use This FrameworkPrimary Metric
RAG systemRAGASFaithfulness > 0.8
Classificationscikit-learn metricsAccuracy, F1
Generation qualityLLM-as-judgeQuality rubric (1-5)
Code generationHumanEvalPass@1, Test pass rate
Model comparisonBenchmark testingMMLU, HellaSwag scores
Safety validationHallucination detectionFaithfulness, Fact-check
Production monitoringOnline evaluationUser feedback, Business KPIs

Python Library Recommendations

LibraryUse CaseInstallation
RAGASRAG evaluationpip install ragas
DeepEvalGeneral LLM evaluation, pytest integrationpip install deepeval
LangSmithProduction monitoring, A/B testingpip install langsmith
lm-evalBenchmark testing (MMLU, HumanEval)pip install lm-eval
scikit-learnClassification metricspip install scikit-learn

Safety Evaluation Priority Matrix

ApplicationHallucination RiskBias RiskToxicity RiskEvaluation Priority
Customer SupportHighMediumHigh1. Faithfulness, 2. Toxicity, 3. Bias
Medical DiagnosisCriticalHighLow1. Factual Accuracy, 2. Hallucination, 3. Bias
Creative WritingLowMediumMedium1. Quality/Fluency, 2. Content Policy
Code GenerationMediumLowLow1. Functional Correctness, 2. Security
Content ModerationLowCriticalCritical1. Bias, 2. False Positives/Negatives

Detailed References

For comprehensive documentation on specific topics:

  • Evaluation types (classification, generation, QA, code): references/evaluation-types.md
  • RAG evaluation deep dive (RAGAS framework): references/rag-evaluation.md
  • Safety evaluation (hallucination, bias, toxicity): references/safety-evaluation.md
  • Benchmark testing (MMLU, HumanEval, domain benchmarks): references/benchmarks.md
  • LLM-as-judge best practices and prompts: references/llm-as-judge.md
  • Production evaluation (A/B testing, monitoring): references/production-evaluation.md
  • All metrics definitions and formulas: references/metrics-reference.md

Working Examples

Python Examples:

  • examples/python/unit_evaluation.py - Basic prompt testing with pytest
  • examples/python/ragas_example.py - RAGAS RAG evaluation
  • examples/python/deepeval_example.py - DeepEval framework usage
  • examples/python/llm_as_judge.py - GPT-4 as evaluator
  • examples/python/classification_metrics.py - Accuracy, precision, recall
  • examples/python/benchmark_testing.py - HumanEval example

TypeScript Examples:

  • examples/typescript/unit-evaluation.ts - Vitest + OpenAI
  • examples/typescript/llm-as-judge.ts - GPT-4 evaluation
  • examples/typescript/langsmith-integration.ts - Production monitoring

Executable Scripts

Run evaluations without loading code into context (token-free):

  • scripts/run_ragas_eval.py - Run RAGAS evaluation on dataset
  • scripts/compare_models.py - A/B test two models
  • scripts/benchmark_runner.py - Run MMLU/HumanEval benchmarks
  • scripts/hallucination_checker.py - Detect hallucinations in outputs

Example usage:

# Run RAGAS evaluation on custom dataset
python scripts/run_ragas_eval.py --dataset data/qa_dataset.json --output results.json

# Compare GPT-4 vs Claude on benchmark
python scripts/compare_models.py --model-a gpt-4 --model-b claude-3-opus --tasks mmlu,humaneval

Integration with Other Skills

Related Skills:

  • `building-ai-chat`: Evaluate AI chat applications (this skill tests what that skill builds)
  • `prompt-engineering`: Test prompt quality and effectiveness
  • `testing-strategies`: Apply testing pyramid to LLM evaluation (unit → integration → E2E)
  • `observability`: Production monitoring and alerting for LLM quality
  • `building-ci-pipelines`: Integrate LLM evaluation into CI/CD

Workflow Integration: 1. Write prompt (use prompt-engineering skill) 2. Unit test prompt (use llm-evaluation skill) 3. Build AI feature (use building-ai-chat skill) 4. Integration test RAG pipeline (use llm-evaluation skill) 5. Deploy to production (use deploying-applications skill) 6. Monitor quality (use llm-evaluation + observability skills)

Common Pitfalls

1. Over-reliance on Automated Metrics for Generation

  • BLEU/ROUGE correlate weakly with human judgment for creative text
  • Solution: Layer LLM-as-judge or human evaluation

2. Ignoring Faithfulness in RAG Systems

  • Hallucinations are the #1 RAG failure mode
  • Solution: Prioritize faithfulness metric (target > 0.8)

3. No Production Monitoring

  • Models can degrade over time, prompts can break with updates
  • Solution: Set up continuous evaluation (LangSmith, custom monitoring)

4. Biased LLM-as-Judge Evaluation

  • Evaluator LLMs have biases (position bias, verbosity bias)
  • Solution: Average multiple evaluations, use diverse evaluation prompts

5. Insufficient Benchmark Coverage

  • Single benchmark doesn't capture full model capability
  • Solution: Use 3-5 benchmarks across different domains

6. Missing Safety Evaluation

  • Production LLMs can generate harmful content
  • Solution: Add toxicity, bias, and hallucination checks to evaluation pipeline

Related skills

FAQ

Which metric is most critical for RAG?

Faithfulness (target above 0.8), which measures whether the answer is grounded in retrieved context and prevents hallucinations.

What evaluation approach fits high volume?

For 1,000+ samples use automated metrics (regex, JSON validation) at near-zero cost; reserve LLM-as-judge and human review for smaller samples.

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