{
  "schema_version": "1.3.0",
  "slug": "what-invariants-prevent-silent-skill-degradation-when-tools-are-composed",
  "title": "What invariants prevent silent skill degradation when tools are composed?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** Multiple tools are composed, their quality contracts are non-trivial, and workflow quality matters to downstream consumers. * **Does not apply when:** Single-tool workflows, or compositions where quality is verified as a",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/what-invariants-prevent-silent-skill-degradation-when-tools-are-composed.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/what-invariants-prevent-silent-skill-degradation-when-tools-are-composed.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/what-invariants-prevent-silent-skill-degradation-when-tools-are-composed.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1059,
    "python_slice_tokens": 383,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The separation between **individual tool quality** (each tool meets its individual accuracy, reliability, and semantics guarantees) and **composed workflow quality** (the chained output meets the workflow's requirements). Relying on individual quality creates the **Composition Skill Decay**: tool A is 90% accurate, tool B is 90% accurate, and the composed A→...",
    "what_was_observed": "In tool-composition agent architectures, failing to verify composition skill produces three primary failure modes: 1. **Accuracy Multiplication Collapse:** A 5-tool pipeline each with 95% accuracy produces 77% workflow accuracy. The user expects 95% because \"each tool is accurate,\" but the workflow quietly operates at 77%. 2. **Error Mode Introduction:** Tool A is deterministic and tool B is non-deterministic. Their ...",
    "condition_of_validity": "* **Applies when:** Multiple tools are composed, their quality contracts are non-trivial, and workflow quality matters to downstream consumers. * **Does not apply when:** Single-tool workflows, or compositions where quality is verified as a unit.",
    "decision_boundary": "1. **Is the workflow a composition of multiple tools?** If no, single-tool quality applies. If yes, proceed. 2. **Is `per_tool_quality_contract_receipt` present for each tool?** If yes, composition quality can be computed. If no, the composition is unquantified. 3. **Does `composition_quality_computation_signature` show composed quality meeting the workflow ...",
    "operational_effect": "1. **Accuracy Collapse Detection:** Composition quality is computed, not assumed. 2. **Error Mode Awareness:** Introduced error modes are surfaced. 3. **Semantic Integrity:** Format compatibility is verified before composition."
  },
  "matched_failure_symptoms": [
    "HTTP_502_503_504_CASCADE"
  ],
  "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": "bcd44e6d754d754ab60d0507fbcabab5ac1faee5e5ef18992be3991ae1f066e5",
    "verified_classes": [
      "CompositionVerdict",
      "ToolQuality",
      "ToolComposition",
      "CompositionPolicy",
      "CompositionManifest",
      "ToolCompositionSkillGuard"
    ],
    "verified_functions": [
      "_hash",
      "evaluate_composition"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib",
      "json"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}