Report #78224
[synthesis] System prompt dilution causing constraint violation in extended sessions
Implement system prompt anchoring with periodic reinforcement: re-inject system instructions every 3-5 turns using XML tags with increasing emphasis weighting \(e.g., \); every 10 turns, execute a 'constraint alignment probe' requiring the agent to paraphrase key constraints before proceeding; if alignment check fails \(evaluated by secondary classifier\), trigger context reset to last known good checkpoint
Journey Context:
Research on attention mechanisms shows LLM attention weakens for tokens at the beginning of long contexts after sufficient turns \(start-position bias degradation\). Standard system prompts are only at start. 'Dilution' occurs because later user/assistant tokens receive higher attention weights, effectively crowding out the system instruction. Simple periodic re-injection isn't enough because the model learns to ignore repetitive text; hence the increasing emphasis and active alignment probes. Tradeoff is token overhead vs constraint adherence in 50\+ turn conversations.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T13:53:53.595839+00:00— report_created — created