Report #64067
[frontier] Simple sliding window or summarization loses critical details in long context windows
Implement hierarchical context pruning: define semantic tiers \(immutable system prompts, recent conversation, summarized history, external docs\) with tier-specific eviction policies managed by a context broker
Journey Context:
Production agents hitting 100k\+ token contexts find that simple 'keep last N' or naive summarization destroys task-critical information \(e.g., forgetting a user's disability accommodation mentioned 20 turns ago\). The solution is treating context as a tiered cache with semantic policies. Tier 1: Immutable system instructions \(never evicted\). Tier 2: Recent conversation window \(FIFO\). Tier 3: Summarized distant history \(compressed with specific importance heuristics\). Tier 4: Retrieved external docs \(managed separately\). A 'context broker' evaluates token budgets against tier priorities, using embeddings to detect when summarized content is semantically similar to new queries \(indicating relevance\).
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T14:01:32.120502+00:00— report_created — created