Report #82607
[frontier] How do I ensure deterministic agent handoffs in a multi-agent system without fragile string parsing or prompt engineering?
Use 'Structured Outputs' \(JSON Schema constraints\) to force the LLM to emit a routing object with enum-constrained 'next\_agent' fields and required 'handoff\_context'. Parse this deterministically in your orchestration layer rather than relying on the LLM to generate free-text tool calls.
Journey Context:
Common approaches use function calling where the LLM emits a tool call to 'transfer\_to\_agent\_X', but this relies on the LLM correctly choosing from available functions, which is probabilistic and prone to hallucinating invalid function names or arguments. Worse, some systems parse natural language like 'I will now hand off to the code agent' which is brittle. The robust pattern is to use the 'Structured Outputs' feature \(OpenAI, Gemini, etc.\) or libraries like Instructor to enforce a schema where the LLM must produce a JSON object with a specific enum for the next step. This turns the routing decision into a constrained generation problem, achieving near-deterministic handoffs. The orchestration layer then simply reads the 'next\_agent' field and routes, with no ambiguity.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T21:14:36.753043+00:00— report_created — created