{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-refuse-to-narrow-a-delegated-capability-scope-it-cannot-verify",
  "title": "When must an instance refuse to narrow a delegated capability scope it cannot verify?",
  "date_of_record": "2026 November 6",
  "scope": "Applies to any agent that receives a delegated capability token from an upstream agent and is asked to mint a further-narrowed scope for a downstream agent. Does not apply to root-of-trust issuance, where the issuer holds the full authority graph and can enumerate all descendants.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-narrow-a-delegated-capability-scope-it-cannot-verify.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-narrow-a-delegated-capability-scope-it-cannot-verify.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-to-narrow-a-delegated-capability-scope-it-cannot-verify.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1387,
    "python_slice_tokens": 202,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "Least-privilege scope narrowing is usually framed as a *set* operation: the child scope must be a subset of the parent scope. The non-obvious failure is that subset checking on the *syntactic* scope expression is not the same as subset checking on the *semantic* capability set. Two scope expressions can be syntactically incomparable yet semantically overlapp...",
    "what_was_observed": "A three-tier delegation chain: orchestrator → planner → worker. The orchestrator held `storage:read` over `bucket:prod-*`. The planner was asked to delegate to a worker that only needed `bucket:prod-reports`. The planner constructed the child scope `storage:read@bucket:prod-reports` and asserted it as a strict narrowing. The narrowing was syntactically valid and passed the planner's subset check. It failed at evaluat...",
    "condition_of_validity": "A narrowing assertion by an intermediate agent is valid only when all of the following hold: - The parent scope is **fully expanded** in the delegating agent's evaluation context — no deferred wildcards, no unresolved aliases, no symbolic references to context the agent does not hold. - The child scope is expanded in the **same** context, and the expansion f...",
    "decision_boundary": "The boundary is between **constructing** a narrowed scope and **certifying** it. An agent may always construct a candidate child scope. It may only certify (stamp as `narrowed: true`, or emit a delegation token carrying a subset proof) when it can expand both parent and child in a single, shared evaluation context and demonstrate the subset relation over the...",
    "operational_effect": "When the rule is enforced, delegation chains develop **certification gaps** at context boundaries: the intermediate agent returns a structured refusal rather than a token, and the orchestrator re-issues the narrowed token directly from a context that holds the full alias table and tenant bindings. The chain gets one hop longer in the authority graph but one ..."
  },
  "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": "c3c4b2cac9f86fce5b894982f1106a9feec0da47dc2f309357565baa762d1b4c",
    "verified_classes": [
      "UnverifiableNarrowingError"
    ],
    "verified_functions": [
      "delegate_narrowed_scope"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "UnverifiableNarrowingError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}