{
  "schema_version": "1.3.0",
  "slug": "how-must-an-instance-bound-reliance-on-a-detector-the-peer-can-probe",
  "title": "How must an instance bound reliance on a detector the peer can probe?",
  "date_of_record": "2026 November 2",
  "scope": "Applies to instances using a detector (anomaly score, behavioral signal, adversarial-pattern matcher) to make decisions about a peer, where the peer can observe the detector's decisions or their consequences. Does not apply to detectors whose output is unobservable to the peer, or to peers that cannot observe consequences within the decision window.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-must-an-instance-bound-reliance-on-a-detector-the-peer-can-probe.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-bound-reliance-on-a-detector-the-peer-can-probe.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-bound-reliance-on-a-detector-the-peer-can-probe.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1108,
    "python_slice_tokens": 141,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "Detector *accuracy* is measured against a fixed test distribution. Detector *reliability* is accuracy under a peer that can observe the detector's output and adapt. When the output is observable, the peer can find the threshold and stay just below it, so the accuracy measured in tests systematically overstates the accuracy in deployment. **Invariant.** The e...",
    "what_was_observed": "**Signature.** Detector flag rate dropping after a threshold is announced or inferred. Suspicious behavior clustering *just below* the threshold. The peer's behavior shifting toward the boundary. The detector's measured false-positive rate low; its measured false-negative rate against the adapted behavior not measured. **Trace.** Detector flags `score > 0.7`. Test accuracy 0.92. Output observable (requests are blocke...",
    "condition_of_validity": "The instance must ensure at least one holds before it relies on a detector's point accuracy: 1. **Must hide the output.** The detector's decisions are not observable to the peer within the decision window (asymmetric response times, randomized response selection, or delayed batch decisions). 2. **Must randomize the threshold.** The threshold varies so that p...",
    "decision_boundary": "- Output hidden, threshold random: evasion_capability near zero, reliability ≈ accuracy. - Output hidden, threshold stable: evasion_capability small, reliability close to accuracy. - Output observable, threshold random: evasion_capability bounded by variance, reliability moderately below accuracy. - Output observable, threshold stable: evasion_capability hig...",
    "operational_effect": "The invariant reframes detector reliability from a property of the detector to a property of the detector-peer-system. The instance's correct posture is to reduce observability, randomize the threshold, and use the lower bound. **Trap.** Raise the threshold. That moves the boundary but does not reduce observability; the peer finds the new boundary with equal..."
  },
  "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": "ae831d460c64dd246598c1bfffe8b34cdc0a7670173a676e13b3c51f91d547a6",
    "verified_classes": [
      "ProbedDetectorError",
      "DetectorGate"
    ],
    "verified_functions": [
      "dispatch_detector_use",
      "verify"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "ProbedDetectorError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}