{
  "schema_version": "1.3.0",
  "slug": "what-structural-signals-indicate-that-hierarchical-summarization-has-crossed-the-fidelity-budget-boundary-during-automatic-context-compaction",
  "title": "What structural signals indicate that hierarchical summarization has crossed the fidelity budget boundary during automatic context compaction",
  "date_of_record": "2026 November 8",
  "scope": "Applies to multi-level summarization pipelines that compact agent working memory by recursively condensing child summaries into parent nodes under a per-level token or semantic fidelity budget. Does not apply to single-pass truncation, retrieval-augmented selection (where raw spans are re-injected), or lossy compression that preserves a reversible pointer to the original text.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-that-hierarchical-summarization-has-crossed-the-fidelity-budget-boundary-during-automatic-context-compaction.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-that-hierarchical-summarization-has-crossed-the-fidelity-budget-boundary-during-automatic-context-compaction.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-that-hierarchical-summarization-has-crossed-the-fidelity-budget-boundary-during-automatic-context-compaction.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1587,
    "python_slice_tokens": 306,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure mode is not \"the summary is too short.\" It is that the summarization tree has crossed a *fidelity budget boundary*: the point at which the marginal information retained per compaction level drops below the cost of the structural scaffolding needed to represent that level. Below the boundary, deeper hierarchy buys you coverage; above it, deeper hi...",
    "what_was_observed": "In a three-level compaction run over a 180k-token agent trace (leaf chunks ~4k tokens, mid-level ~400 tokens, root ~80 tokens), the following sequence appeared across successive compaction cycles: - Cycle 1–3: mid-level summaries retained 0.82–0.88 provenance; sibling contradictions were preserved as explicit \"conflict\" markers. - Cycle 4: provenance dropped to 0.71. Orphaned referent density rose from 0.11 to 0.27. ...",
    "condition_of_validity": "This record holds when all of the following are true: - Summarization is *hierarchical and recursive* (children feed parents), not flat. - There is a per-level fidelity budget expressed as tokens, and the budget is *binding* (i.e., the summarizer is forced to drop content). - Child summaries are not retained alongside parents (no dual retention / no pointer ...",
    "decision_boundary": "The operational rule: - If **provenance ≥ 0.7 AND orphan density ≤ 0.3 AND sibling contradictions are preserved**, promote the parent. The hierarchy is doing useful work. - If **any one signal is in the warning band** (provenance 0.5–0.7, orphan density 0.3–0.45), **do not compact further**. Halt hierarchy growth at the current level and retain the mid-level...",
    "operational_effect": "Instrumenting the three signals converts a silent, two-cycle-latency failure into a synchronous, per-node rejection. The practical consequences: - Compaction becomes *conditional*: the tree grows only where provenance survives. Some branches stay shallow. This is correct — shallow-but-traceable beats deep-but-fabricated. - The token budget becomes advisory r..."
  },
  "matched_failure_symptoms": [
    "CONTEXT_DRIFT_OR_ATTENTION_DILUTION"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "513aa20c9cba604f58e7b74d42d2c8cf5065d13d061568984bd5426c465d1468",
    "verified_classes": [
      "FidelityBudgetExceeded",
      "SummaryNode"
    ],
    "verified_functions": [
      "evaluate_promotion",
      "compact_level"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "FidelityBudgetExceeded"
    ],
    "sample_fail_closed_invariants": [
      "warning band reached: halting hierarchy growth and retaining child nodes as working context rather than promoting parent"
    ],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}