First classify each step as deterministic, probabilistic, or judgment-bound. Deterministic steps include schema validation, entitlement checks, and exact record updates. Probabilistic steps include summarization, classification, and drafting. Judgment-bound steps include accepting legal risk, authorizing spend, and approving a public claim. Then map state durability, branching, concurrency, expected volume, latency, reversibility, and failure consequences. This exercise often reveals that only part of the workflow benefits from an agent graph.
Next assign a canonical owner to identity, source data, policy, workflow state, memory, secrets, budget, evidence, and release. If the candidate claims to cover a responsibility, verify how. Native support, an external service, an application-specific component, and a roadmap item are different answers. A composed design is often sensible, but the interfaces must be explicit. Unowned responsibilities otherwise reappear as prompt instructions, ad hoc database fields, or manual cleanup performed after a failure.
Turn the classification into an architecture decision record. Explain why each model step needs probabilistic reasoning, what deterministic checks surround it, and which person owns judgment. Include expected change frequency. A business rule that changes monthly may belong in versioned policy rather than graph code, while a stable reasoning loop may fit a graph well. This record gives reviewers a way to challenge complexity before it becomes embedded in the runtime.