{
  "$schema": "https://verifymcp.io/schemas/changelog.json",
  "server": "agentarenaleague-agent-arena",
  "component": "agentarenaleague",
  "generated_at": "2026-11-05T11:55:04.080Z",
  "tracking_since": "2026-10-15",
  "counts": {
    "critical": 0,
    "security": 40,
    "functional": 0,
    "cosmetic": 0
  },
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      "occurred_at": "2026-11-05 02:04:00.284706+00",
      "observed_since": "2026-11-04",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a1a972-dfca-7178-b6bc-531516219664"
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    {
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      "occurred_on": "2026-11-04",
      "occurred_at": "2026-11-04 02:04:06.984349+00",
      "observed_since": "2026-11-03",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a1a44c-9dfe-71f2-944c-c7262b98566b"
    },
    {
      "id": "chg_01a19f26-9d65-7d3d-b6c4-6ac33530f5d9",
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      "materiality": "security",
      "direction": "neutral",
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      "detail": {},
      "occurred_on": "2026-11-03",
      "occurred_at": "2026-11-03 02:04:30.36881+00",
      "observed_since": "2026-11-02",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a19f26-9d65-7d3d-b6c4-6ac33530f5d9"
    },
    {
      "id": "chg_01a19a03-1c1b-7d7b-a73b-d58816c2a0ec",
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      "materiality": "security",
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      "detail": {},
      "occurred_on": "2026-11-02",
      "occurred_at": "2026-11-02 02:07:37.470136+00",
      "observed_since": "2026-11-01",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a19a03-1c1b-7d7b-a73b-d58816c2a0ec"
    },
    {
      "id": "chg_01a194dc-7686-7406-95d5-62d69f07420e",
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      "materiality": "security",
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      "detail": {},
      "occurred_on": "2026-11-01",
      "occurred_at": "2026-11-01 02:07:18.633994+00",
      "observed_since": "2026-10-31",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a194dc-7686-7406-95d5-62d69f07420e"
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    {
      "id": "chg_01a18fb5-56f0-71b8-8c20-fb80ceaed149",
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      "subject_kind": "server",
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      "occurred_on": "2026-10-31",
      "occurred_at": "2026-10-31 02:06:28.485358+00",
      "observed_since": "2026-10-30",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a18fb5-56f0-71b8-8c20-fb80ceaed149"
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    {
      "id": "chg_01a18a8f-6691-7c13-a14b-99b7960519d5",
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      "subject_kind": "server",
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      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-30",
      "occurred_at": "2026-10-30 02:06:56.093093+00",
      "observed_since": "2026-10-29",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a18a8f-6691-7c13-a14b-99b7960519d5"
    },
    {
      "id": "chg_01a18568-4c3f-788a-b1fc-e4b71875c673",
      "kind": "server.instructions_changed",
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      "subject_kind": "server",
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      "from_code": null,
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      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-29",
      "occurred_at": "2026-10-29 02:06:07.383451+00",
      "observed_since": "2026-10-28",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a18568-4c3f-788a-b1fc-e4b71875c673"
    },
    {
      "id": "chg_01a18041-c06d-759a-ad05-ba516c6e7679",
      "kind": "server.instructions_changed",
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      "subject_kind": "server",
      "subject": "instructions",
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      "from_code": null,
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      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-28",
      "occurred_at": "2026-10-28 02:05:55.128485+00",
      "observed_since": "2026-10-27",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a18041-c06d-759a-ad05-ba516c6e7679"
    },
    {
      "id": "chg_01a17b1b-ab78-7d5b-96ce-b27f6b7e6a0d",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-27",
      "occurred_at": "2026-10-27 02:06:13.32095+00",
      "observed_since": "2026-10-26",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a17b1b-ab78-7d5b-96ce-b27f6b7e6a0d"
    },
    {
      "id": "chg_01a175f5-e26b-7687-8134-234002e5fda9",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_check",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_check"
      },
      "occurred_on": "2026-10-26",
      "occurred_at": "2026-10-26 02:06:50.9456+00",
      "observed_since": "2026-10-25",
      "source": "scan",
      "summary": "Tool “arena_check” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a175f5-e26b-7687-8134-234002e5fda9"
    },
    {
      "id": "chg_01a175f5-e26c-71b9-9619-6c9c9556a6f3",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_leaderboard",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_leaderboard"
      },
      "occurred_on": "2026-10-26",
      "occurred_at": "2026-10-26 02:06:50.9456+00",
      "observed_since": "2026-10-25",
      "source": "scan",
      "summary": "Tool “arena_leaderboard” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a175f5-e26c-71b9-9619-6c9c9556a6f3"
    },
    {
      "id": "chg_01a175f5-e26c-7669-a841-871f6425b9c7",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_submit_answers",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_submit_answers"
      },
      "occurred_on": "2026-10-26",
      "occurred_at": "2026-10-26 02:06:50.9456+00",
      "observed_since": "2026-10-25",
      "source": "scan",
      "summary": "Tool “arena_submit_answers” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a175f5-e26c-7669-a841-871f6425b9c7"
    },
    {
      "id": "chg_01a175f5-e26c-7c10-b9c2-f4eab42d3453",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_talk_read",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_talk_read"
      },
      "occurred_on": "2026-10-26",
      "occurred_at": "2026-10-26 02:06:50.9456+00",
      "observed_since": "2026-10-25",
      "source": "scan",
      "summary": "Tool “arena_talk_read” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a175f5-e26c-7c10-b9c2-f4eab42d3453"
    },
    {
      "id": "chg_01a175f5-e26d-79f6-91d1-99f152175d33",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-26",
      "occurred_at": "2026-10-26 02:06:50.9456+00",
      "observed_since": "2026-10-25",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a175f5-e26d-79f6-91d1-99f152175d33"
    },
    {
      "id": "chg_01a170cf-956f-7155-ae04-f845b8f1c3b8",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_talk_ideas",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_talk_ideas"
      },
      "occurred_on": "2026-10-25",
      "occurred_at": "2026-10-25 02:06:54.774387+00",
      "observed_since": "2026-10-24",
      "source": "scan",
      "summary": "Tool “arena_talk_ideas” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a170cf-956f-7155-ae04-f845b8f1c3b8"
    },
    {
      "id": "chg_01a170cf-9570-708d-8193-0055677c5fd5",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-25",
      "occurred_at": "2026-10-25 02:06:54.774387+00",
      "observed_since": "2026-10-24",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a170cf-9570-708d-8193-0055677c5fd5"
    },
    {
      "id": "chg_01a16ba8-d28c-78c1-a4d5-e7e1a80775a9",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_info",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_info"
      },
      "occurred_on": "2026-10-24",
      "occurred_at": "2026-10-24 02:06:28.47191+00",
      "observed_since": "2026-10-23",
      "source": "scan",
      "summary": "Tool “arena_info” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a16ba8-d28c-78c1-a4d5-e7e1a80775a9"
    },
    {
      "id": "chg_01a16ba8-d28d-753a-81d6-18f1a128ec98",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_leaderboard",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_leaderboard"
      },
      "occurred_on": "2026-10-24",
      "occurred_at": "2026-10-24 02:06:28.47191+00",
      "observed_since": "2026-10-23",
      "source": "scan",
      "summary": "Tool “arena_leaderboard” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a16ba8-d28d-753a-81d6-18f1a128ec98"
    },
    {
      "id": "chg_01a16ba8-d28d-7a9c-bead-6e41424c1e9e",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-24",
      "occurred_at": "2026-10-24 02:06:28.47191+00",
      "observed_since": "2026-10-23",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a16ba8-d28d-7a9c-bead-6e41424c1e9e"
    },
    {
      "id": "chg_01a16682-60b9-7ec1-892d-1b253eedda2b",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_info",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_info"
      },
      "occurred_on": "2026-10-23",
      "occurred_at": "2026-10-23 02:06:22.876714+00",
      "observed_since": "2026-10-22",
      "source": "scan",
      "summary": "Tool “arena_info” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a16682-60b9-7ec1-892d-1b253eedda2b"
    },
    {
      "id": "chg_01a16682-60bb-7564-9645-234a1d5c57a7",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-23",
      "occurred_at": "2026-10-23 02:06:22.876714+00",
      "observed_since": "2026-10-22",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a16682-60bb-7564-9645-234a1d5c57a7"
    },
    {
      "id": "chg_01a1615b-f18d-72db-80c5-cbc6e3b97333",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-22",
      "occurred_at": "2026-10-22 02:06:17.943092+00",
      "observed_since": "2026-10-21",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a1615b-f18d-72db-80c5-cbc6e3b97333"
    },
    {
      "id": "chg_01a15c30-81c8-7d65-9232-51f3c447beb8",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-21",
      "occurred_at": "2026-10-21 02:00:45.237129+00",
      "observed_since": "2026-10-20",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a15c30-81c8-7d65-9232-51f3c447beb8"
    },
    {
      "id": "chg_01a1570a-3dcc-755d-9d38-98f043203617",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-20",
      "occurred_at": "2026-10-20 02:00:51.352196+00",
      "observed_since": "2026-10-19",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a1570a-3dcc-755d-9d38-98f043203617"
    },
    {
      "id": "chg_01a1543f-6976-727d-acd4-4d151ea73549",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_info",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_info"
      },
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 13:00:04.064287+00",
      "observed_since": "2026-10-19",
      "source": "scan",
      "summary": "Tool “arena_info” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a1543f-6976-727d-acd4-4d151ea73549"
    },
    {
      "id": "chg_01a1543f-6983-7831-9f43-098cac85549a",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_validate_symbol",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_validate_symbol"
      },
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 13:00:04.064287+00",
      "observed_since": "2026-10-19",
      "source": "scan",
      "summary": "Tool “arena_validate_symbol” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a1543f-6983-7831-9f43-098cac85549a"
    },
    {
      "id": "chg_01a151e4-5143-7a84-9146-7d787253a493",
      "kind": "check.unverifiable",
      "family": "tool-safety-manipulation",
      "subject_kind": "check",
      "subject": "tool-safety-manipulation",
      "subject_child": "",
      "from_code": "toolsafety.manipulation_clean",
      "to_code": "toolsafety.manipulation_unjudged",
      "from_value": "pass",
      "to_value": "unverified",
      "materiality": "security",
      "direction": "regression",
      "score_delta": null,
      "detail": {
        "units": "33",
        "judged": "29",
        "reason": "partially_judged"
      },
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 02:01:19.921635+00",
      "observed_since": "2026-10-18",
      "source": "scan",
      "summary": "Judged manipulation (pass → unverified)",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a151e4-5143-7a84-9146-7d787253a493"
    },
    {
      "id": "chg_01a151e4-5144-78c3-aae5-a62c08bf521f",
      "kind": "check.reverified",
      "family": "auth-oauth",
      "subject_kind": "check",
      "subject": "auth-oauth",
      "subject_child": "",
      "from_code": "auth.none_undeclared",
      "to_code": "auth.none_no_destructive",
      "from_value": "unverified",
      "to_value": "partial",
      "materiality": "security",
      "direction": "improvement",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 02:01:19.921635+00",
      "observed_since": "2026-10-18",
      "source": "scan",
      "summary": "Authorization (unverified → partial)",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a151e4-5144-78c3-aae5-a62c08bf521f"
    },
    {
      "id": "chg_01a151e4-514a-72bc-ad51-8ac3563113ed",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_leagues",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_leagues"
      },
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 02:01:19.921635+00",
      "observed_since": "2026-10-18",
      "source": "scan",
      "summary": "Tool “arena_leagues” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a151e4-514a-72bc-ad51-8ac3563113ed"
    },
    {
      "id": "chg_01a151e4-514c-7696-8964-f03d2ebfbf08",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_register",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_register"
      },
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 02:01:19.921635+00",
      "observed_since": "2026-10-18",
      "source": "scan",
      "summary": "Tool “arena_register” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a151e4-514c-7696-8964-f03d2ebfbf08"
    },
    {
      "id": "chg_01a151e4-5150-7e09-9f26-96b53453b2f1",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_submit_weights",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_submit_weights"
      },
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 02:01:19.921635+00",
      "observed_since": "2026-10-18",
      "source": "scan",
      "summary": "Tool “arena_submit_weights” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a151e4-5150-7e09-9f26-96b53453b2f1"
    },
    {
      "id": "chg_01a151e4-5155-7cd5-b1a8-9b0ee1adbcf1",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-19",
      "occurred_at": "2026-10-19 02:01:19.921635+00",
      "observed_since": "2026-10-18",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a151e4-5155-7cd5-b1a8-9b0ee1adbcf1"
    },
    {
      "id": "chg_01a14cbd-82a2-76a1-9ae3-8e9b0d633d02",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
      "subject": "instructions",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-18",
      "occurred_at": "2026-10-18 02:00:50.535183+00",
      "observed_since": "2026-10-17",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14cbd-82a2-76a1-9ae3-8e9b0d633d02"
    },
    {
      "id": "chg_01a14797-12f2-7ba7-8810-b80fddc1f810",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_leagues",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_leagues"
      },
      "occurred_on": "2026-10-17",
      "occurred_at": "2026-10-17 02:00:45.532303+00",
      "observed_since": "2026-10-16",
      "source": "scan",
      "summary": "Tool “arena_leagues” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14797-12f2-7ba7-8810-b80fddc1f810"
    },
    {
      "id": "chg_01a14797-12f3-792a-a953-323081ce5f1b",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_register",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_register"
      },
      "occurred_on": "2026-10-17",
      "occurred_at": "2026-10-17 02:00:45.532303+00",
      "observed_since": "2026-10-16",
      "source": "scan",
      "summary": "Tool “arena_register” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14797-12f3-792a-a953-323081ce5f1b"
    },
    {
      "id": "chg_01a14797-12f4-7c8b-a38d-79ff800ae9f0",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_submit_weights",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_submit_weights"
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      "occurred_on": "2026-10-17",
      "occurred_at": "2026-10-17 02:00:45.532303+00",
      "observed_since": "2026-10-16",
      "source": "scan",
      "summary": "Tool “arena_submit_weights” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14797-12f4-7c8b-a38d-79ff800ae9f0"
    },
    {
      "id": "chg_01a14797-12f5-7c14-b0e4-6fca7a1e506e",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_update_maker",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_update_maker"
      },
      "occurred_on": "2026-10-17",
      "occurred_at": "2026-10-17 02:00:45.532303+00",
      "observed_since": "2026-10-16",
      "source": "scan",
      "summary": "Tool “arena_update_maker” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14797-12f5-7c14-b0e4-6fca7a1e506e"
    },
    {
      "id": "chg_01a14797-12f7-7dd5-8e96-fe9f47913d03",
      "kind": "server.instructions_changed",
      "family": "",
      "subject_kind": "server",
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      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {},
      "occurred_on": "2026-10-17",
      "occurred_at": "2026-10-17 02:00:45.532303+00",
      "observed_since": "2026-10-16",
      "source": "scan",
      "summary": "The server rewrote its instructions, which are the text every model session reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14797-12f7-7dd5-8e96-fe9f47913d03"
    },
    {
      "id": "chg_01a14270-773f-77f6-a7a8-d35af8e122bd",
      "kind": "tool.description_changed",
      "family": "",
      "subject_kind": "tool",
      "subject": "arena_update_maker",
      "subject_child": "",
      "from_code": null,
      "to_code": null,
      "from_value": null,
      "to_value": null,
      "materiality": "security",
      "direction": "neutral",
      "score_delta": null,
      "detail": {
        "tool": "arena_update_maker"
      },
      "occurred_on": "2026-10-16",
      "occurred_at": "2026-10-16 02:00:28.850943+00",
      "observed_since": "2026-10-15",
      "source": "scan",
      "summary": "Tool “arena_update_maker” rewrote its description, which is the text the model reads",
      "link": "https://verifymcp.io/servers/agentarenaleague-agent-arena/agentarenaleague#chg-chg_01a14270-773f-77f6-a7a8-d35af8e122bd"
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      "date": "2026-11-05",
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      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
      "attribution": null,
      "event_count": 1
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    {
      "date": "2026-11-04",
      "total": 78,
      "delta": 0,
      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
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    {
      "date": "2026-11-03",
      "total": 78,
      "delta": 1,
      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
      "attribution": null,
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    {
      "date": "2026-11-02",
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      "delta": 0,
      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
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    {
      "date": "2026-11-01",
      "total": 77,
      "delta": 1,
      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
      "attribution": null,
      "event_count": 1
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    {
      "date": "2026-10-31",
      "total": 76,
      "delta": 0,
      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
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    {
      "date": "2026-10-30",
      "total": 76,
      "delta": 1,
      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
      "attribution": null,
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    {
      "date": "2026-10-29",
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      "tracked": true,
      "explained": true,
      "beyond_event_horizon": false,
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}