The math is unforgiving. Ten agents, each 95% reliable individually, chained sequentially: 0.95^10 = 0.598. Your system succeeds 60% of the time. Add five more agents and you are at 46%.

This is not a theoretical concern. A landmark study analyzing over 1,600 execution traces across seven popular multi-agent frameworks found failure rates between 41% and 87%. Carnegie Mellon put leading agent systems at 30-35% task completion on multi-step benchmarks. Gartner predicts 40% of agentic AI projects will be cancelled by 2027.

The pattern is familiar. Microservices hit the same wall in 2015. The solution was the service mesh: a dedicated infrastructure layer for service-to-service communication with built-in reliability, observability, and traffic management.

AI agents in 2026 have no equivalent.

The Reliability Compounding Penalty