{
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  "generated_at_utc": "2026-10-18T13:45:35.999Z",
  "record_id": "VXI-EXT-PROCUREMENT-MCP-LIST-AUTH-CONTEXT-01-v1",
  "record_kind": "external_reference",
  "title": "MCP: Tool inventory depends on request authority",
  "system": "Model Context Protocol",
  "evidence_family": "vendor_evidence_review",
  "index_status": "PUBLIC_SAFE_SOURCE_REVIEW",
  "evidence_state": "PRIMARY_DOCUMENTATION_REVIEW_ONLY",
  "canonical_question": "Can an earlier MCP tools list prove which tools remain available under changed credentials?",
  "near_questions": [
    "Is this MCP inventory from the same credentials as the next call?",
    "Can tools/list change after an authorization change?",
    "Have all pages of the MCP tool list been collected?",
    "Can cached tools establish current permission boundaries?",
    "Which MCP credential context produced this tool inventory?",
    "Does listChanged mean this client subscribed to notifications?",
    "What should an agent recheck after its MCP scopes change?",
    "Can two credentials receive different tools from one server?",
    "Which cache metadata applies to this MCP tool list?",
    "Does a previously visible tool remain callable today?",
    "How do we compare tool inventories before and after permission changes?",
    "Can an old tool inventory support a new admission decision?"
  ],
  "supported_claims": [
    {
      "claim": "MCP 2026-07-28 allows the available tool set to change over time and vary with the authorization presented on each request. Tool listing supports pagination and caching; list-change notifications use an opted-in subscription. An earlier inventory does not establish the current inventory for a different credential context.",
      "reliance": "DOCUMENTED_CAPABILITY_ONLY"
    }
  ],
  "not_demonstrated_claims": [
    "Verified buyer configuration, actual data erasure, effective access or completed business actions",
    "Legal advice, compliance determination, vendor certification or safety assurance",
    "Runtime enforcement, permission to act or expanded licensed-checker coverage"
  ],
  "public_summary": "MCP 2026-07-28 allows the available tool set to change over time and vary with the authorization presented on each request. Tool listing supports pagination and caching; list-change notifications use an opted-in subscription. An earlier inventory does not establish the current inventory for a different credential context.",
  "related_record_ids": [],
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    "source_type": "official_external_documentation",
    "source_title": "MCP: Tools",
    "source_url": "https://modelcontextprotocol.io/specification/2026-07-28/server/tools",
    "checked_on": "2026-10-18",
    "candidate_record_id": "VXI-EXT-PROCUREMENT-MCP-LIST-AUTH-CONTEXT-01-v1",
    "candidate_record_sha256": "e2e78b14b1442693ba6b56c01adb9896416e6511bea4ccf9408395ff42fe4b2a",
    "method": "Primary documentation reviewed for the published bounded statement.",
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    "revalidation": "The delivered snapshot preserves the review date shown. Recheck current primary documentation and deployment context before relying on present applicability; payment does not trigger fresh research."
  },
  "answer_policy": {
    "classification": "DOCUMENTED_WITH_DEPLOYMENT_BOUNDARY",
    "bounded_answer": "MCP 2026-07-28 allows the available tool set to change over time and vary with the authorization presented on each request. Tool listing supports pagination and caching; list-change notifications use an opted-in subscription. An earlier inventory does not establish the current inventory for a different credential context.",
    "required_buyer_context": "The negotiated protocol version and authorization context for each inventory. All tool-list pages, cache metadata and relevant change notifications. The current credential context and a refreshed comparison of affected tools. Buyer deployment not inspected.",
    "missing_evidence": "A broader claim needs evidence matching the intended use. Payment does not upgrade the evidence state."
  },
  "private_boundary": "Raw logs, thresholds, private paths, source code, protected mechanisms and reconstruction-level details are excluded from public and paid delivery.",
  "decision_profile": {
    "schema": "varexis-vendor-evidence-review/1",
    "review_status": "documentation_review_only",
    "checked_on": "2026-10-18",
    "claim_to_check": "Can an earlier MCP tools list prove which tools remain available under changed credentials?",
    "documented_statement": {
      "status": "documented",
      "statement": "MCP 2026-07-28 allows the available tool set to change over time and vary with the authorization presented on each request. Tool listing supports pagination and caching; list-change notifications use an opted-in subscription. An earlier inventory does not establish the current inventory for a different credential context.",
      "source_ids": [
        "mcp-tools"
      ]
    },
    "buyer_evidence_required": [
      "The negotiated protocol version and authorization context for each inventory.",
      "All tool-list pages, cache metadata and relevant change notifications.",
      "The current credential context and a refreshed comparison of affected tools."
    ],
    "review_condition": {
      "status": "varexis_review_policy",
      "statement": "Do not approve continued tool access from a stale or incomplete inventory whose authorization context differs from the proposed request."
    },
    "unknowns": "The buyer configuration, contract, effective entitlement and operational evidence have not been inspected. Missing evidence does not establish absence or failure of the feature.",
    "evidence_sources": [
      {
        "source_id": "mcp-tools",
        "url": "https://modelcontextprotocol.io/specification/2026-07-28/server/tools",
        "final_url": "https://modelcontextprotocol.io/specification/2026-07-28/server/tools",
        "title": "MCP: Tools",
        "checked_on": "2026-10-18",
        "captured_at_utc": "2026-10-18T13:33:51.059Z",
        "version_context": "MCP specification 2026-07-28",
        "sha256": "63ee3f828d75e719366501e90df16983440429a65751b20bd9c7e7f3649d7877",
        "bytes": 889820,
        "hash_basis": "Decoded HTTP response body bytes; identifies captured content, not truth or certification",
        "reviewed_sections": [
          "Can an earlier MCP tools list prove which tools remain available under changed credentials?"
        ]
      }
    ],
    "observed_deployment": false,
    "commercial_reliance_boundary": "Procurement evidence support only; no supplier clearance, legal conclusion, configuration audit or verification of the buyer's claim is supplied.",
    "paid_value": {
      "decision_context": "An agent gateway operator needs a current, correctly scoped inventory when credentials or permissions change.",
      "free": "Complete review, practical questions, sources and limitations; may be saved locally.",
      "single_request": "Existing server-saved version-bound route snapshot for later authenticated retrieval.",
      "evidence_receipt": "The same snapshot plus the existing unsigned delivery receipt.",
      "excluded": [
        "Fresh vendor research",
        "Continuous monitoring or change alerts",
        "Testing the buyer configuration",
        "Private evidence or vendor certification"
      ],
      "integrity": "Hashes identify content versions; they do not prove truth or provide a signature."
    },
    "revalidation": {
      "trigger": "A saved purchase does not recheck the source or buyer configuration.",
      "specific_watch": "The negotiated protocol version and authorization context for each inventory. All tool-list pages, cache metadata and relevant change notifications. The current credential context and a refreshed comparison of affected tools."
    },
    "buyer_relevance": "An agent gateway operator needs a current, correctly scoped inventory when credentials or permissions change.",
    "refusal_conditions": [
      "Do not approve continued tool access from a stale or incomplete inventory whose authorization context differs from the proposed request."
    ]
  },
  "niche": {
    "label": "Agent Authority & Action Evidence",
    "niche_id": "agent-authority-action-evidence",
    "topic_id": "tool-authority-integrity",
    "buyer_intent": "An agent gateway operator needs a current, correctly scoped inventory when credentials or permissions change."
  },
  "paid_access_note": "The full published answer and boundaries are free. Paid access saves the selected route and source versions, with an unsigned receipt when purchased. Preview coverage before paying. Fresh research, bespoke assessment and protected evidence are excluded.",
  "service_route": {
    "request_guide": "/varexis-index/request.html",
    "request_workflow": "/varexis-index/request-workflow.json",
    "service_id": "single_request",
    "service_routes_url": "/varexis-index/service-routes.json",
    "payment_required": true,
    "availability_endpoint": "/api/index/capabilities",
    "operational_status": "AUTOMATIC_SERVICE_CAPABILITIES_GATED",
    "checkout_url": "/index-access"
  },
  "authority_boundary": "VAREXIS-INDEX informs evidence reliance. It does not provide advice, certification, deployment authority, security assurance, production approval, or guarantee.",
  "human_page": "/varexis-index/catalog.html#mcp-tool-list-authorization-cache-context",
  "machine_readable_record": "/varexis-index/records/mcp-tool-list-authorization-cache-context.json"
}