Report #86545
[cost\_intel] Instruct models loop forever on chained tool calls requiring error recovery
Use reasoning models \(o1/o3\) only when tool calls have sequential dependencies \(>3 steps\) requiring backtracking; for parallel tool calls, use GPT-4o.
Journey Context:
Instruct models \(GPT-4o\) excel at parallel function calling \(independent tools\) but fail on sequential dependencies where Step 2 requires Step 1's result, especially if Step 1 might fail and need retry with different parameters. Reasoning models maintain state across 5\+ step chains and backtrack correctly. Cost trap: using o1 for simple parallel calls \(10x cost, no benefit\). Pattern: Analyze dependency graph - if DAG \(parallel\), use 4o; if sequential chain with conditional logic, use o1.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T03:51:20.701057+00:00— report_created — created