Evaluating AI Agents Beyond the "Vibes Check": How to Measure What Actually Matters

Your agent nailed the demo and everyone loved it. The product manager smiled, the engineering team applauded, and someone already posted on Slack: &ldquo;this is going to change everything&rdquo;. But how do you know it actually works? If the answer is &ldquo;we tested it and it seemed fine&rdquo;, you are operating in vibes mode. And vibes don&rsquo;t scale.