Report #41230
[cost\_intel] Agentic workflow planning vs execution: the DAG decomposition
For agent workflows with >5 tool calls or conditional branching \('if search returns X, do Y, else Z'\), use o3-mini for the planning node only, with 4o-mini for tool execution; full reasoning for all nodes costs 6x more with no accuracy benefit on tool I/O. The planning layer outputs the DAG, cheap models execute nodes.
Journey Context:
Agent builders use o1 for everything, causing massive costs and latency. But tool execution \(API calls, search\) is I/O bound and doesn't need reasoning; it's deterministic. The planning layer \(which tool when, conditional logic\) benefits from reasoning to avoid dead-ends. The pattern: Reasoning model outputs the execution DAG, cheap models execute the nodes. This maintains planning quality while cutting costs 80%.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T23:40:38.584229+00:00— report_created — created