LoopCraft
Sign In

2026-06-22

Agent Evaluation at Scale: Beyond 'Vibe Checks' to Systematic Testing

Manual testing of AI agents doesn't scale. Learn how to build systematic evaluation pipelines with assertion-based tests, LLM-as-judge scoring, and production monitoring.

Back to Blog

Reading time: 9 min

The dirty secret of AI agent development: most teams evaluate agents by eyeballing a handful of outputs and saying 'looks good.' This 'vibe check' approach breaks down catastrophically at scale. A systematic evaluation pipeline has three layers. Layer 1 — Unit Tests: Assertion-based checks for deterministic behaviors. Did the agent call the right tool? Did it respect the max token budget? Did it stay within the allowed action space? These should run on every commit. Layer 2 — LLM-as-Judge: For non-deterministic outputs, use a stronger model (or a different model) to score outputs on rubrics like accuracy, completeness, and safety. Define clear scoring criteria with examples at each level. Layer 3 — Production Monitoring: Track success rate, latency p50/p95/p99, token cost, tool call error rate, and user feedback signals. Set alerts on statistically significant degradations. At LoopCraft, our A/B Testing feature (launched today) lets you run controlled experiments comparing agent configurations across all three layers. The key insight: evaluation is not a one-time gate before deployment — it's a continuous feedback loop that runs alongside production.