Evidence row 544936

What was observed

{
  "count": 5,
  "tools": [
    {
      "description": "Grade the user's answer to a practice question from get_practice_question. Use this when the user replies with their choice (for example \"B\" or \"I think it is C\"): pass the question_id and their choice. Returns whether the answer is correct, the correct choice, why each choice is right or wrong, and the FAA citations. It also returns save_progress_url, a pplfree.com link where the user can save the answers from this chat to their study progress on that site, and save_token: pass it back as previous_token on the next check_answer call so one link collects every answer in the chat (up to 20, valid for 7 days). Nothing is stored unless the user opens the link.",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "choice": {
            "description": "The choice the user picked: its label (e.g. \"b\" or \"B\").",
            "maxLength": 20,
            "type": "string"
          },
          "previous_token": {
            "description": "The save_token from the previous check_answer call in this chat, if any, so the save link keeps every answer. Omit on the first answer.",
            "maxLength": 4096,
            "type": "string"
          },
          "question_id": {
            "description": "The questionId returned by get_practice_question.",
            "maxLength": 120,
            "type": "string"
          }
        },
        "required": [
          "question_id",
          "choice"
        ],
        "type": "object"
      },
      "name": "check_answer"
    },
    {
      "description": "Fetch one full ground-school lesson: its summary, why it matters in flight, the learning objectives it covers, and a link to read it. Use this after search_faa_knowledge when the user wants the whole topic rather than a single answer, or when they ask to study or learn a subject properly. Call list_curriculum first if you do not already have a lesson key.",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "lessonKey": {
            "description": "Lesson key, e.g. \"as.lesson.vfr-minimums\". From list_curriculum.",
            "maxLength": 120,
            "type": "string"
          }
        },
        "required": [
          "lessonKey"
        ],
        "type": "object"
      },
      "name": "get_lesson"
    },
    {
      "description": "Return private-pilot practice questions written for this course in the style of the FAA knowledge test (not actual FAA test questions), each with its answer choices, its topic, a question_id and a link to try it on pplfree.com. The correct answer is withheld by default so the user can attempt the question first. Once the user has answered, call check_answer with that question_id and their choice to grade it (or call this tool again with the question_id and reveal_answer: true to show the answer without grading). Use this when the user wants to be quizzed, asks for practice or test questions, wants to check their understanding of a topic, or is preparing for the FAA private-pilot knowledge test. Optionally scope it to a topic.",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "count": {
            "description": "How many questions to return (1-5, default 1).",
            "maximum": 5,
            "minimum": 1,
            "type": "integer"
          },
          "question_id": {
            "description": "A question_id from an earlier call, to return that exact question (typically with reveal_answer: true). Overrides topic and count.",
            "maxLength": 120,
            "type": "string"
          },
          "reveal_answer": {
            "default": false,
            "description": "Include the correct choice and the explanation. Default false: leave it off until the user has attempted the question.",
            "type": "boolean"
          },
          "topic": {
            "description": "Optional topic to draw from, e.g. \"airspace\", \"weather\", \"aerodynamics\", \"regulations\", \"navigation\", \"weight-balance\", \"systems\". Omit for any topic.",
            "maxLength": 80,
            "type": "string"
          }
        },
        "required": [],
        "type": "object"
      },
      "name": "get_practice_question"
    },
    {
      "description": "List the ground-school curriculum: modules and the published lessons in each, with their keys. Use this to orient yourself before get_lesson, to answer \"what does the course cover\", or to help a user plan what to study next.",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "module": {
            "description": "Optional module key to expand, e.g. \"MOD-08\". Omit for all modules.",
            "maxLength": 40,
            "type": "string"
          }
        },
        "required": [],
        "type": "object"
      },
      "name": "list_curriculum"
    },
    {
      "description": "Answer a US private-pilot (FAA) ground-school question from a source-cited curriculum. Use this whenever the user asks about FAA regulations, airspace, VFR weather minimums, weight and balance, aerodynamics, aircraft systems, navigation, weather theory, human factors, or private-pilot certification requirements. Returns short passages, each with the FAA citation it came from (e.g. \"14 CFR 91.155\", \"PHAK Ch. 15\") and a link to the lesson. Cite those labels in your answer.",
      "inputSchema": {
        "additionalProperties": false,
        "properties": {
          "limit": {
            "description": "How many passages to return (1-8, default 4).",
            "maximum": 8,
            "minimum": 1,
            "type": "integer"
          },
          "query": {
            "description": "The user's question, in their own words.",
            "maxLength": 500,
            "minLength": 3,
            "type": "string"
          }
        },
        "required": [
          "query"
        ],
        "type": "object"
      },
      "name": "search_faa_knowledge"
    }
  ]
}

What the leaf hashes

{"body":"37aa2cba0ae98ce5c409ca063a053cf5a1cd55d0dee9227a989cd67ab1481a0c","id":544936,"kind":"mcp.tools","method":"probe.mcp/1","observed_us":1793132230074679,"prev":null,"subject":"8bb90c9a-435a-4b0b-b2d7-52834d9f5ecb","subject_kind":"endpoint"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of 2026-10-27 (273461 rows).

1. 0xc9de9dc204f8c7e54c0906e6840c184a5a2efd10797a824b54900a1e7372c835
2. 0x21aadf74928f70da6ba7cbaccd525016fa2204692cb6e1811a6c8e798b008179
3. 0x80b8bada457c35a774ffa8293de43a0ecd210fb8d85d706787211eb24481a919
4. 0x2913c2b7073438e5285e224fdf8c444f96e4981a2a48d3bae845097ef802088d
5. 0x27405a6e0aff0faf048a461ef82e7f7bccfccb36ebee346e33a7e8d3ac406b03
6. 0xf639732aeb4a9d4d35e003912bd10a6fd9635f0781fdaf7ced5b32ae161f2f0b
7. 0x160fc658e8716a1df91ecc12d4d5bac43fe5b97e03e82cb4d2082d8d55a9527a
8. 0xe57c5fef3b47f2903ca141b6cbfa959fea2e1c1313aa69c20bf10eb330d89a9c
9. 0x9e50205ef0e4f27d637bf7290c75537ea4078a02ed820c44626155d0ff61f914
10. 0xab6aa42ff70ef9b1bb0432341341797bcdc6c7977be485231550b0a2006a6579
11. 0x2cf261bd2238b74a95bc8d9823ad293037abc046c04aeff157cde0c97263ed73
12. 0xd16d7e5f125e1d777c4add2d34626605aa2a6b03288469395f9c1f401de8e9e1
13. 0x938752e9acd199cd15f468392bc2dd8eefc52293e7144e30b87b241ca6b2513b
14. 0xcc49fd573532e5a29f5be4033f62a2eff71456c020bd2258312b98e95cfe301e
15. 0x969cd44e5a4e8dc3110540398fbf689659eb51df735c1cda5d8f021ef9ff5683
16. 0xa94627de1af0e823832e05a9069b304ecccb8c0cdb8f9cfc4f2039bfb9799dc5
17. 0xdf1105afdc109de3c09a98fc8a3864159ad964e6f49b635c105a27a1e1f14310
18. 0x2bf8151e5f157dd183b9de6fa00469551932a7a6e3f33a694895000ac9061197
19. 0x9fc354c0ea3efc3f1b6548bb77ea902a50f2c9647647ea61592efce2bd795699

Day root

0xdd77e5e99da32c3f154180d63e3c3e6fe11e896a2c6896412ef6b5c4bcf7e795

Chained

0x23bb4dfd09f55c15ac3962f53578e02c6114d5bfd9bb451cf8794fb6e2817ef4

Published

On Arc Testnet, block 69414147: 0xb2ebd83aafeb765a0ce66e76aefb133ed06606c98038fd56191e2bcd1dcb77b4