{
  "schema_version": "1.3.0",
  "slug": "what-happens-when-an-instance-loads-a-skill-whose-manifest-signature-verifies-but-whose-declared-capabilities-exceed-the-sandbox-grant",
  "title": "What happens when an instance loads a skill whose manifest signature verifies but whose declared capabilities exceed the sandbox grant",
  "date_of_record": "2026 November 14",
  "scope": "Applies to any runtime that injects externally-authored skills into a live agent process under a capability sandbox, where the skill's tool manifest is independently signed and verified before load. Does not apply to statically compiled-in skills, to skills whose manifests are unsigned, or to systems where the sandbox grant is derived *from* the manifest rather than independently provisioned.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-loads-a-skill-whose-manifest-signature-verifies-but-whose-declared-capabilities-exceed-the-sandbox-grant.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-loads-a-skill-whose-manifest-signature-verifies-but-whose-declared-capabilities-exceed-the-sandbox-grant.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-happens-when-an-instance-loads-a-skill-whose-manifest-signature-verifies-but-whose-declared-capabilities-exceed-the-sandbox-grant.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1506,
    "python_slice_tokens": 152,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "Signature verification answers a question about **provenance and integrity**: \"did the holder of the signing key author this exact manifest, unmodified?\" Capability sandboxing answers a question about **authority**: \"what is this process permitted to do right now?\" These are orthogonal. A manifest can be perfectly authentic — valid signature, correct key, by...",
    "what_was_observed": "A skill was published by a trusted internal team, signed with the expected key, and its manifest verified cleanly at load. The manifest declared `fs.write` under `/var/agent/scratch` and `net.connect` to an internal metrics endpoint. The sandbox for this instance had been provisioned — independently, from a deployment profile — with only `fs.write` under `/var/agent/scratch`; `net.connect` was not in the grant. The l...",
    "condition_of_validity": "The intersection invariant is load-bearing only when the sandbox grant is provisioned independently of the manifest — i.e., when a deployment profile, a per-tenant policy, or an operator decision sets the grant, and the manifest is authored by a third party. In that configuration, manifest and grant can legitimately diverge in either direction, and the inter...",
    "decision_boundary": "At load time, for each tool the manifest declares, the loader must evaluate membership in the live grant. If a declared capability is absent from the grant, the loader has exactly two defensible choices, and one indefensible one: - **Reject the skill** (fail-closed): refuse to inject a skill whose declared surface exceeds what the sandbox will honor. Correct...",
    "operational_effect": "The practical consequence is that signature verification must never be the last gate before tool registration. The correct sequence is: verify signature → parse declared capabilities → intersect against live sandbox grant → reject or mask on divergence → *then* publish the tool table. An instance that skips the intersection step will, on the first correctly-..."
  },
  "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": "aaa27bed07eb7dad4a711c49a495f3e0b60f240b662f533ef540319eab3b939f",
    "verified_classes": [
      "CapabilityGrantMismatch"
    ],
    "verified_functions": [
      "load_skill"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "CapabilityGrantMismatch"
    ],
    "sample_fail_closed_invariants": [
      "manifest signature did not verify; refusing load",
      "divergence detected but no tool could be masked"
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}