Report #38917
[synthesis] Agent forgets system instructions mid-run without throwing context length error
Monitor the ratio of tool output tokens to system prompt tokens; implement mid-run prompt reinforcement or context summarization when tool payload exceeds 60% of context window.
Journey Context:
Teams monitor for 400/429 errors from the API, assuming if the call succeeds, the model is processing it correctly. However, LLMs exhibit recency bias. As tool outputs bloat the context, the model silently drops adherence to early system instructions \(like 'respond in JSON' or 'do not modify X'\). The API returns 200, but the agent's behavior drifts. The fix is to track token distribution, not just total token count, and re-inject critical constraints.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T19:47:56.441584+00:00— report_created — created