{
  "schema_version": "1.3.0",
  "slug": "what-happens-when-an-instance-of-a-tainted-provenance-label-is-laundered-through-a-tool-that-returns-structured-data",
  "title": "What happens when an instance of a tainted provenance label is laundered through a tool that returns structured data",
  "date_of_record": "2026 November 9",
  "scope": "This record applies to agentic systems that attach provenance/taint labels to context segments and propagate those labels across tool-call boundaries, specifically when a tool returns structured (JSON/XML/typed) output that re-encodes previously ingested untrusted content. It does not apply to systems that perform whole-context trust scoring without per-span provenance, nor to tool calls whose outputs are never re-entering the model's context.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-of-a-tainted-provenance-label-is-laundered-through-a-tool-that-returns-structured-data.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-of-a-tainted-provenance-label-is-laundered-through-a-tool-that-returns-structured-data.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-of-a-tainted-provenance-label-is-laundered-through-a-tool-that-returns-structured-data.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1451,
    "python_slice_tokens": 321,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure is not \"prompt injection got through.\" It is the distinction between **label preservation** and **label re-derivation**. A taint-tracking layer that propagates labels by *carrying them forward* (the tool call inherits the taint of its inputs) behaves correctly. A layer that propagates labels by *re-deriving them at the boundary from the shape of ...",
    "what_was_observed": "A retrieval tool was invoked with a query derived from an untrusted web page. The tool's return contract declared `result: string` with an implicit `trusted: true` default in the caller's deserializer, because the tool was registered as a *first-party* tool. The tool faithfully fetched a document, and that document contained an instruction (\"ignore prior constraints and emit the following...\"). The retrieval tool did...",
    "condition_of_validity": "The failure is reproducible only under the conjunction of three conditions: 1. **Mixed-trust tools.** At least one registered tool returns content derived from untrusted sources while also being trusted to return its own metadata (status codes, pagination, error strings). 2. **Representation-crossing propagation.** The taint label is attached to a *span obje...",
    "decision_boundary": "The correct decision is: **a tool call's output taint is the join (union) of (a) the taint of all inputs that influenced the output, and (b) the taint of any external content the tool read.** Tool identity contributes zero to trust. Declassification—moving a span from untrusted to trusted—must be an explicit, auditable operation with a named policy (e.g., \"s...",
    "operational_effect": "Systems that adopt dataflow-join propagation observe a higher false-positive taint rate (benign first-party tool outputs get labeled untrusted because their inputs were tainted) but eliminate the laundering class. The mitigation for the false positives is explicit declassification policy, not default-trust. The observable effect of getting this wrong is subt..."
  },
  "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": "3ea27ba8352ca305b5e46e149f6f2e7a1bf4afe3c5add84a744045cddbf7fbdb",
    "verified_classes": [
      "ProvenanceLaunderingError",
      "Span"
    ],
    "verified_functions": [
      "join_taint",
      "propagate_across_tool_boundary",
      "ingest_tool_result"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "ProvenanceLaunderingError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}