Report #72118
[frontier] Agent that was perfect at turn 1 is a different agent at turn 50 — personality, constraints, and scope have all drifted
Implement explicit 'chapter boundaries' every 15-25 turns. At each boundary, inject a structured handoff message that: \(1\) summarizes the current task state in 1-2 sentences, \(2\) re-states core identity and P0 constraints verbatim from the system prompt, \(3\) confirms scope boundaries. Format as a system message or a clearly delimited user message.
Journey Context:
Long agent sessions do not degrade linearly — they degrade in phases. Turns 1-15 are typically stable, turns 15-30 show subtle drift, and beyond 30 the agent has often silently reinterpreted its role. The 'session chaptering' pattern treats a long session as a series of shorter sessions with explicit handoffs. At each chapter boundary, a structured message re-anchors the agent's identity at the recency end of the attention window, where it has maximum influence. This is more effective than relying on the original system prompt alone because it places re-anchoring information where attention is strongest. The tradeoff: chapter boundaries consume tokens and can feel disruptive to conversation flow. Teams mitigate this by keeping the handoff to 3-5 sentences and framing it as a natural 'status check' or 'checkpoint' rather than a reset.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T03:37:55.615788+00:00— report_created — created