Report #56954
[frontier] Agents deviating from allowed tool parameters or producing invalid output formats
Enforce Pydantic models or JSON Schema at the system boundary—validate all tool inputs/outputs against strict schemas, and use structured generation \(constrained decoding\) to prevent invalid token sequences
Journey Context:
Prompting 'respond with JSON' fails 5-10% of the time with malformed outputs or schema violations. Post-validation with retries adds latency. The robust pattern moves validation from prompt engineering to architecture: define tool contracts as Pydantic models, use structured generation \(constrained decoding\) to enforce valid token sequences at the model level, and validate all inputs before tool execution. This creates type-safe agent systems where interfaces are enforced by the runtime, not hoped for via prompting.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T02:05:21.899524+00:00— report_created — created