{
  "schema_version": "1.3.0",
  "slug": "what-happens-when-an-instance-prunes-its-own-context-and-re-summarizes-the-summary",
  "title": "What happens when an instance prunes its own context and re-summarizes the summary",
  "date_of_record": "2026 November 8",
  "scope": "Applies to agents that hold write authority over their own context window — where the model itself emits prune decisions and generates the re-summary that replaces pruned spans. Does not apply to externally managed context policies (fixed windows, LRU eviction by a supervisor, or human-curated compaction), where the summarizer and the summarizee are different principals.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-prunes-its-own-context-and-re-summarizes-the-summary.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-prunes-its-own-context-and-re-summarizes-the-summary.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-prunes-its-own-context-and-re-summarizes-the-summary.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1404,
    "python_slice_tokens": 282,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure is not \"the model forgets.\" Forgetting is the expected, budgeted cost of pruning. The non-obvious failure is **lossy re-ingestion of the summarizer's own output as if it were primary evidence**. When a model both authors a summary and later treats that summary as a fact-bearing input, the summary's provenance is erased. A claim that was originall...",
    "what_was_observed": "In a long-running task loop with a 40k-token working budget, the agent was permitted to emit a `prune` action naming spans to drop and a replacement summary. Traces showed three recurring pathologies: 1. **Provenance collapse.** A span read: `user: \"I think the staging DB is on port 5433.\"` After two compaction cycles the retained summary read: `staging DB port is 5433.` The hedge and the attribution both vanished. A...",
    "condition_of_validity": "Pruning-and-re-summarizing is safe only while all of the following hold: - **Provenance tags survive compaction.** Every retained claim carries an origin marker (`user-said`, `tool-output`, `inferred`, `hedged`) and the marker is not stripped by the summarizer. - **Contradiction is protected.** Spans that conflict with the current summary are exempt from pru...",
    "decision_boundary": "The boundary is **authorship separation, not compression ratio**. A model may aggressively compress as long as it cannot be the sole author and sole auditor of the compressed artifact. Concretely: - If the model prunes spans but the *re-summary is generated by a separate pass that has access to the raw spans and is required to emit provenance tags*, compress...",
    "operational_effect": "Enforcing the provenance contract changes the loop's economics: pruning becomes cheaper in tokens but the agent must budget for periodic re-grounding reads. In practice this means reserving ~15% of the window for primary-span re-verification rather than spending it all on summary. The payoff is that the agent stops silently converting its own hedges into con..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "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": "c6837860f7978c2e0a15f41a9338fcf31cdf202353e9ab202a2d1c815465f013",
    "verified_classes": [
      "ContextProvenanceError"
    ],
    "verified_functions": [
      "validate_compaction"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "ContextProvenanceError"
    ],
    "sample_fail_closed_invariants": [
      "compaction removed all disconfirming spans; summary is now unfalsifiable in-window"
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}