I lead a backend team of seven. Last quarter our PR throughput jumped 40 percent after we standardized on agentic tooling. Management loved the dashboard. Then I actually looked at what was shipping. Median PR size dropped, but median review time per line went up. Two of my mid-level engineers started opening PRs I could tell they hadn't read end-to-end. The agent had factored a service into four files where one would do, and nobody pushed back because the tests passed. We ate that debt in Q1. A migration that should have taken a week took three because the abstractions were load-bearing in ways the original authors couldn't explain. I had to sit with one engineer and walk through his own code. The productivity gain is real at the diff layer and imaginary at the system layer. What we actually sped up is the part that was already cheap: typing. What we slowed down is the part that was always expensive: understanding. I don't think the dashboards are going to catch this for another two quarters.