The 4 Layer Agent Evaluation Framework
The hardest part in building AI apps is not models. Its Evaluation
Traditional testing gave us false confidence.
Unit tests passed
Integration tests passed
Code review approved
๐๐๐ ๐ฝ๐ฟ๐ผ๐ฑ๐๐ฐ๐๐ถ๐ผ๐ป ๐ณ๐ฎ๐ถ๐น๐ฒ๐ฑ
๐ช๐ต๐ ๐๐ ๐ฒ๐๐ฎ๐น๐๐ฎ๐๐ถ๐ผ๐ป ๐ถ๐ ๐ฑ๐ถ๐ณ๐ณ๐ฒ๐ฟ๐ฒ๐ป๐:
AI agents are non-deterministic. Standard testing doesnโt work.
You need to validate what traditional testing ignores:
โ Semantic correctness (Does it understand intent?)
โ Reasoning correctness (Does it think logically?)
๐๐ผ๐ฟ ๐๐๐ฎ๐ฟ๐๐๐ฝ๐, ๐ฟ๐ฒ๐น๐ถ๐ฎ๐ฏ๐ถ๐น๐ถ๐๐ = ๐๐๐ฟ๐๐ถ๐๐ฎ๐น.
No second chances. Every bug erodes trust you canโt rebuild.
๐ช๐ต๐ฎ๐ ๐ ๐ฑ๐ถ๐๐ฐ๐ผ๐๐ฒ๐ฟ๐ฒ๐ฑ:
Issues in one evaluation stage cascaded downstream โ untraceable production failures.
The fix? Compartmentalize. Test tools separately from reasoning, reasoning separately from outputs, outputs separately from metrics.
Last week, Googleโs โ๐ฆ๐๐ฎ๐ฟ๐๐๐ฝ ๐ง๐ฒ๐ฐ๐ต๐ป๐ถ๐ฐ๐ฎ๐น ๐๐๐ถ๐ฑ๐ฒ: ๐๐ ๐๐ด๐ฒ๐ป๐๐โ validated exactly what I learned the expensive way. The guide has the multi-evaluation framework for evaluating AI agents.
๐ง๐ต๐ฒ ๐ฐ-๐๐ฎ๐๐ฒ๐ฟ ๐๐ฟ๐ฎ๐บ๐ฒ๐๐ผ๐ฟ๐ธ:
๐๐ฎ๐๐ฒ๐ฟ ๐ญ: Component Testing Deterministic unit tests for tools and APIs โ Catches 90% of basic failures โ Takes 2 days to set up. Donโt skip it.
๐๐ฎ๐๐ฒ๐ฟ ๐ฎ: Trajectory Evaluation โก ๐ ๐ข๐ฆ๐ง ๐๐ฅ๐๐ง๐๐๐๐ Validate reasoning path, not just outputs โ Does it reason correctly? โ Right tools with right parameters? โ Does it learn from outputs?
๐๐ฎ๐๐ฒ๐ฟ ๐ฏ: Outcome Evaluation What users actually see: โ Factual accuracy โ Helpfulness โ Completeness
๐๐ฎ๐๐ฒ๐ฟ ๐ฐ: System Monitoring Track real-world performance: โ Tool failure rates โ Cost per conversation โ User feedback scores
๐ช๐ต๐ฎ๐ ๐ ๐น๐ฒ๐ฎ๐ฟ๐ป๐ฒ๐ฑ:
Issues cascade. Compartmentalize testingโsaved weeks of debugging.
Trajectory validation cut debugging time 95%.
Cost monitoring isnโt optional for startups.
๐ช๐ต๐ฎ๐ ๐โ๐ฑ ๐ฑ๐ผ ๐ฑ๐ถ๐ณ๐ณ๐ฒ๐ฟ๐ฒ๐ป๐๐น๐:
Donโt: Ship based on โit looks good in demosโ Do: Build evaluation into CI/CD from day one
Donโt: Test only final outputs Do: Validate every reasoning step
Donโt: Skip component testing Do: Start with Layer 1. Always.
P.S: Googleโs โStartup Technical Guide: AI Agentsโ link in comments.