When the hype around autonomous multi-agent swarms started, I built a complex assistant to plan, execute and self-correct workflows end to end. Within weeks of live deployment, it became an unmaintainable token pit that got lost four steps deep into reasoning loops and quietly failed without throwing errors. It quickly became clear that the hardest part of building real agents isn't making the model smarter but building external guardrails that keep the system on the rails when the LLM strays. ...