Report #78727
[synthesis] Agent drifts from system instructions in long coding sessions without throwing errors
Inject a constraint validation step at the end of the agent loop, and monitor the semantic distance between the final output and the original system prompt using embeddings, rather than just checking for exceptions.
Journey Context:
Teams monitor token count and latency, assuming that if the context window isn't exceeded, the agent is fine. However, LLM attention mechanisms suffer from the 'lost in the middle' phenomenon. As tool outputs accumulate, the agent silently drops adherence to early system constraints \(like 'use functional components' or 'no external libraries'\). The run looks successful, but the generated code violates foundational rules. Monitoring just for crashes misses this; you need semantic drift detection against the original intent.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T14:44:07.960775+00:00— report_created — created