The Agent Planning Module: A Hidden Architectural Seam
Most agentic systems are built with a single architectural assumption that goes unstated: the LLM handles both planning and execution in the same inference call. Ask it to complete a ten-step task, and the model decides what to do, does it, checks the result, decides what to do next—all in one continuous ReAct loop. This feels elegant. It also collapses under real workloads in a way that's hard to diagnose because the failure mode looks like a model quality problem rather than a design problem.
The agent planning module—the component responsible purely for task decomposition, dependency modeling, and sequencing—is the seam most practitioners skip. It shows up only when things get hard enough that you can't ignore it.
