Multi-Agent Error Cascades: The Double Pendulum Problem Nobody Talks About

Your agents are a chaos machine 🎯 So HumanLayer dropped their Advanced Context Engineering piece last week, and buried in it is this absolute banger of a line: "Bad research -> bad plan -> bad code. A single wrong line in research cascades to widespread errors." That's Dex Horthy describing what happens when you chain AI agents together without checkpoints. And it's the exact same mechanics as a double pendulum. You know the double pendulum, yeah? Simple physics demo. One pendulum hanging from another. The top one swings predictably. The bottom one goes absolutely mental. Tiny changes in the initial swing of the top pendulum produce wildly different trajectories in the bottom one. Chaos theory in action. Looks like it's possessed. Multi-agent AI systems are double pendulums. Your research agent makes a small mistake. Misidentifies which module handles authentication. Gets one import path wrong. Reads an outdated API signature. Tiny error. Barely noticeable in the research output. Your planning agent reads that research and builds a plan around the wrong assumption. The plan isn't obviously wrong. It's coherent. It just starts from a slightly incorrect foundation. The deviation from reality is bigger now but still plausible-looking. Your implementation agent reads that plan and writes hundreds of lines of code. Code that's internally consistent but built on a foundation of sand. The cascade is complete. One wrong line in research became a hundred wrong lines in code. Why more agents makes this worse, not better Here's the bit that does my head in. The whole pitch of multi-agent systems is "more agents = better results." Specialise each agent. Divide the labour. Sounds reasonable. But every agent you add to the chain is another joint in the pendulum. Every handoff is another point where small errors amplify. A three-agent pipeline (research, plan, implement) has two handoff points. A five-agent pipeline has four. Each one is a potential chaos amplification. Sean Moran