Do I need an agent? Do I need LangGraph?

• If next steps are fixed, use a sequence of functions or a workflow.
• If next information actions genuinely vary, a bounded agent may help.
• Use LangGraph when explicit state, branching, review pauses, or recovery justify it; a short read-only loop can remain simple.

Evidence: compare fixed workflow, single agent, and extra specialists on task completion, calls, cost, and failure modes. Add multi-agent roles only for demonstrated benefits.