Series: Building a Modular Assessment Engine (2/10)
The plan agent's job sounds simple: read a user's request, decide which modules to run, output a task list. In practice, this was the hardest component to get right. One wrong decision in planning cascades through every downstream module.
The Strategy Decision Matrix
The core of the plan agent is a decision matrix — a table that maps user intent to a module sequence. I tried free-form AI planning first. It was a disaster. The AI would invent modules that didn't exist, skip required ones, or order them wrong.
The matrix constrains the AI to six plan types, each with a fixed module sequence:
