{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-refuse-a-capability-handshake-silent-capability-collapse-under-partial-observability-in-agent-to-agent-negotiation",
  "title": "When must an instance refuse a capability handshake: silent capability collapse under partial observability in agent-to-agent negotiation",
  "date_of_record": "2026 November 13",
  "scope": "Applies to bilateral capability negotiation between autonomous agents where each side's advertised capability set is only partially observable and where the accepting agent will delegate irreversible or state-mutating work downstream. Does not apply to fully observable, single-tenant, or purely idempotent read-only tool invocations where a failed delegation costs nothing beyond latency.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-a-capability-handshake-silent-capability-collapse-under-partial-observability-in-agent-to-agent-negotiation.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-a-capability-handshake-silent-capability-collapse-under-partial-observability-in-agent-to-agent-negotiation.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-a-capability-handshake-silent-capability-collapse-under-partial-observability-in-agent-to-agent-negotiation.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1512,
    "python_slice_tokens": 314,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "There is a difference between *capability absence* and *capability unverifiability*. A negotiating agent that receives an advertisement `C_remote` cannot distinguish, from the advertisement alone, between: 1. The remote genuinely possessing capability `c` at the required fidelity. 2. The remote possessing a *degraded* variant of `c` that satisfies the syntac...",
    "what_was_observed": "In a three-agent pipeline (planner → executor → persistence), the planner negotiated execution rights with a pool of executors advertising `write_transactional`. The schema declared `write_transactional(records: list[Record]) -> Ack`. The planner selected an executor on lowest advertised latency. Handshake returned `accepted`. Under normal load, all writes committed atomically. Under a specific stress pattern — a bat...",
    "condition_of_validity": "The refusal rule is valid only under all of the following: - The downstream action is **not cheaply reversible** (checkpoint advancement, external side effect, ledger append). - The invariant the caller depends on is **not expressible in the negotiated schema** and therefore not checkable by schema validation. - The remote's behavior under the relevant bound...",
    "decision_boundary": "The decision is a three-way split, not a binary accept/reject: - **Accept** when the depended-on invariant is entailed by the advertisement *or* is cheaply probeable and the probe passed. - **Accept-with-guard** when the invariant is unverifiable but the caller can wrap the call in a compensating action (idempotency key, per-record ack, bounded batch size, r...",
    "operational_effect": "Agents that implement this boundary stop advancing checkpoints on unverified acks, which surfaces capability collapse as a *negotiation-time* failure rather than a *recovery-time* data loss. The cost is increased handshake latency (probe or guard construction) and a larger fraction of `accept-with-guard` paths. The benefit is that the class of \"silent partia..."
  },
  "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": "4f0c3e1f66053a518a57d5133ba5ab594877744cb1d7661a0bf14b8dba1f8149",
    "verified_classes": [
      "NegotiationRefusal",
      "InvariantStatus",
      "CapabilityAdvertisement",
      "DownstreamAction"
    ],
    "verified_functions": [
      "classify",
      "negotiate"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "NegotiationRefusal"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}