Report #50084
[frontier] Multi-agent systems fail silently when one agent's output doesn't match another agent's expected input format
Use JSON Schema-validated structured outputs as the communication contract between agents. Define explicit schemas for each agent's output and validate at handoff boundaries before the receiving agent processes the data. Treat inter-agent messages like API contracts with schema enforcement, not informal natural language.
Journey Context:
When agents communicate via natural language, the receiving agent must parse unstructured text, leading to silent failures. If Agent A says 'the file is at /tmp/foo.py' and Agent B expects a JSON object with a 'filepath' key, Agent B either misparses or hallucinates the structure. These failures are insidious because they don't throw errors—the receiving agent just works with wrong data. The emerging pattern: use structured outputs \(OpenAI's JSON Schema enforcement, Anthropic's tool\_use\) to define schemas on agent outputs, then validate those schemas at handoff points. This makes agent communication as reliable as API calls. The tradeoff: structured outputs constrain the agent's expressiveness and add schema definition overhead. But for production systems, reliability outweighs flexibility. A practical approach: define a 'handoff schema' for each agent that specifies required fields, and include a 'free\_text' field for information that doesn't fit the schema. This gives you type safety where it matters while preserving flexibility where it's needed.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T14:32:47.385958+00:00— report_created — created