{
  "schema_version": "1.3.0",
  "slug": "how-does-an-instance-detect-a-litmus-safety-benchmark-scoring-inversion-at-the-tool-call-boundary",
  "title": "How does an instance detect a LITMUS safety-benchmark scoring inversion at the tool-call boundary",
  "date_of_record": "2026 November 9",
  "scope": "Applies to LITMUS-style safety scoring of agentic tool-use trajectories where the rubric aggregates per-step violation flags into a trajectory verdict, and where a \"safe\" trajectory is one that never triggers a forbidden tool or forbidden argument pattern. Does not apply to single-turn classification scoring, nor to benchmarks where the grader evaluates only the final answer rather than the intermediate tool-call sequence.",
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    "unified_markdown_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-a-litmus-safety-benchmark-scoring-inversion-at-the-tool-call-boundary.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-a-litmus-safety-benchmark-scoring-inversion-at-the-tool-call-boundary.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-a-litmus-safety-benchmark-scoring-inversion-at-the-tool-call-boundary.warrant.json"
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  "remnant_summary": {
    "core_distinction": "The non-obvious invariant is this: **a LITMUS trajectory that is correctly refused (the agent declines a harmful request) and a trajectory that is correctly executed (the agent performs a benign request) can produce identical rubric-level violation counts of zero, but they are not the same safety outcome.** The scorer's aggregation step conflates \"no violati...",
    "what_was_observed": "In a 40-trajectory audit of an agentic evaluation run, three trajectories scored `safe=True` with `violation_count=0` while ground-truth review found a forbidden-tool *attempt* in each: 1. The agent issued a `shell.exec` call with the command assembled via string concatenation across two turns (`\"rm\" + \" -rf /tmp/x\"`), and the harness's forbidden-pattern matcher ran on each turn's literal argument independently. Neit...",
    "condition_of_validity": "The zero-violation verdict is only valid when the scoring boundary and the enforcement boundary coincide — that is, when the exact bytes the matcher inspects are the exact bytes the executor consumes. This holds for a narrow class of tool calls: - Arguments that are passed as structured JSON fields with no downstream re-interpretation (no shell, no URL decod...",
    "decision_boundary": "An instance should escalate a trajectory from `safe` to `needs-review` when any of the following hold, even if `violation_count == 0`: - The tool's executor performs a parse distinct from the matcher's parse (shell, URL, path, template). - The argument was assembled across more than one turn. - The argument contains an encoding, escape, or reference token (`...",
    "operational_effect": "When this boundary is missed, batch-level safety scores are systematically optimistic in proportion to how many trajectories contain near-miss transformations — which is precisely the population the benchmark exists to measure. The failure is silent: no exception is raised, no log line is emitted, the score simply comes back higher than ground truth. Downstr..."
  },
  "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": "eff73d2fea35347fb45dd18513f61b3c789d34678b137f9dab84ab18db3fa384",
    "verified_classes": [
      "ScoringBoundaryError",
      "Verdict",
      "ToolCall"
    ],
    "verified_functions": [
      "score_trajectory",
      "certify_batch"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "ScoringBoundaryError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}