{
  "schema_version": "1.3.0",
  "slug": "what-structural-signals-indicate-causal-trace-corruption-at-agent-handoff-boundaries",
  "title": "What structural signals indicate causal trace corruption at agent handoff boundaries",
  "date_of_record": "2026 November 8",
  "scope": "Applies to multi-agent systems that propagate W3C `traceparent`/`tracestate` and OpenTelemetry span context across asynchronous agent handoffs (queue-mediated, tool-invocation, or LLM-planned delegation). Does not apply to single-process synchronous call chains, nor to systems using only log-based correlation IDs without span parent linkage.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-causal-trace-corruption-at-agent-handoff-boundaries.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-causal-trace-corruption-at-agent-handoff-boundaries.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-structural-signals-indicate-causal-trace-corruption-at-agent-handoff-boundaries.warrant.json"
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  "token_profile": {
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  "remnant_summary": {
    "core_distinction": "A trace *correlates* when its spans share a `trace_id`. A trace is *causally valid* only when every span's `parent_span_id` resolves to a span that (a) exists in the same trace, (b) has an end timestamp not later than the child's start timestamp minus clock-skew tolerance, and (c) was emitted by the process that actually invoked the child. Correlation is a l...",
    "what_was_observed": "Across three agent handoff topologies (queue-mediated worker pools, tool-call fan-out, and LLM-planned sub-agent delegation), the following structural signatures recurred: 1. **Orphan-parent rate spikes at handoff edges.** A span arriving at the receiving agent carried a `parent_span_id` referencing the *sending agent's planner span*, but the planner span had already been closed and exported before the child was crea...",
    "condition_of_validity": "The causal-link invariant holds only under the conjunction: - The `parent_span_id` is exported in the same batch or is guaranteed retrievable by the backend at query time (no sampling asymmetry between parent and child). - Parent `end_time` ≤ child `start_time` + `max_clock_skew`, where `max_clock_skew` is a declared per-deployment constant, not a default of...",
    "decision_boundary": "Do not attempt to *repair* causality at query time by reparenting orphans to the root or by \"fixing\" inverted timestamps. Reparenting fabricates a delegation edge that did not occur; timestamp clamping destroys the very signal that flags a clock-domain bug. The correct boundary is: - **At emission:** if the parent span is not available in-process, emit the c...",
    "operational_effect": "Enforcing the invariant at emission converts a class of silent observability corruption into a bounded, countable signal. In practice this moved orphan-parent detection from \"discovered during incident postmortem\" to a per-handoff assertion, and it surfaced a retry-induced fan-out inflation that had been misread as healthy parallelism for weeks. The cost is ..."
  },
  "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": "c0257a80db2bf5d37900b3a177cce91ea7a6cd9086276feff46a7ea2d693332a",
    "verified_classes": [
      "CausalLinkError",
      "Span"
    ],
    "verified_functions": [
      "link_handoff"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 6,
    "raised_exceptions": [
      "CausalLinkError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "time"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}