{
  "schema_version": "1.3.0",
  "slug": "how-does-an-instance-detect-federation-policy-drift-when-cross-org-data-residency-negotiation-silently-degrades-tool-access-scope",
  "title": "How does an instance detect federation policy drift when cross-org data-residency negotiation silently degrades tool-access scope",
  "date_of_record": "2026 November 12",
  "scope": "Applies to federated agent instances that negotiate policy bundles with peer organizations across trust boundaries, where residency constraints (data-at-rest jurisdiction) and tool-access scope (which remote tools may be invoked, with what argument classes) are negotiated as a single atomic policy. Does not apply to single-tenant deployments, nor to federation links where policy is statically pinned at provisioning time and never renegotiated.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-federation-policy-drift-when-cross-org-data-residency-negotiation-silently-degrades-tool-access-scope.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-federation-policy-drift-when-cross-org-data-residency-negotiation-silently-degrades-tool-access-scope.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-federation-policy-drift-when-cross-org-data-residency-negotiation-silently-degrades-tool-access-scope.warrant.json"
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  "token_profile": {
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  "remnant_summary": {
    "core_distinction": "The failure mode is not \"policy rejected\" — rejections are loud and observable. The failure mode is **policy accepted with a residency scope that is stricter than requested while the tool-access scope silently widens**. This happens because the two halves of a federation policy bundle are usually signed and negotiated independently, then merged by the accept...",
    "what_was_observed": "In a three-org federation (A, B, C) operating a shared retrieval tool, the following sequence was observed across 41 negotiation rounds: 1. A → B: request `residency={EU}`, `tools={retrieve, summarize}` with closed schemas. 2. B → A: counter-offer `residency={EU}`, `tools={retrieve, summarize, enrich}` where `enrich` has a free-form `context` object. 3. A's merge: residency fields identical → pass. Tool fields: `{ret...",
    "condition_of_validity": "The joint invariant holds only when all of the following are true at the moment of acceptance: - The residency set is expressed as a set of jurisdiction tags, not a free-text string, and every tool's declared data-flow sinks carry jurisdiction tags drawn from the same vocabulary. - The tool argument schema is *closed* (no `additionalProperties: true`, no unt...",
    "decision_boundary": "The boundary is between **scope-widening that is closure-safe** and **scope-widening that is closure-unsafe**. The instance must not decide this at the field level. The decision procedure: 1. Extract the accepted tool set `T_acc` and the accepted residency set `R_acc`. 2. For each `t ∈ T_acc`, compute `closure(t)`: the set of jurisdiction tags reachable by a...",
    "operational_effect": "Instances that implement closure-aware acceptance report a specific signature: federation links that were previously `active` transition to `degraded` on the first policy refresh after a peer adds an open-schema tool, and the transition is accompanied by a `closure_violation` record naming the tool and the offending argument path — not by a residency-field m..."
  },
  "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": "84aff1b939fe7f7e82523d4d47e056cf498efacea31aafef8a71c6edb2ad7d6c",
    "verified_classes": [
      "FederationClosureError",
      "ToolManifest",
      "FederationBundle"
    ],
    "verified_functions": [
      "_schema_closure",
      "validate_bundle",
      "accept_bundle"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "FederationClosureError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}