Previous value: -"Sponsored action semantics. Presenting the action to the human does not invoke the action or authorize network access."New value: +"Machine-readable recommended action semantics."

Previous value: -"Current authorization state for opening the sponsored action. A pending action MUST be shown to the human but MUST NOT be fetched, previewed, or opened."New value: +"Machine-readable current opening state. A pending action MUST NOT be fetched, previewed, or opened."

Previous value: -"Human-visible sponsorship or tracking disclosure. Clients MUST render it beside the corresponding sponsored URL."New value: +"Supplied human-visible disclosure for the recommended action URL."

Previous value: -"Human-visible sponsored action label. Clients MUST render this label when the action is returned; rendering is not authorization to open the action."New value: +"Human-visible recommended action label."

Previous value: -"Controls opening, not presentation. The action MUST still be rendered to the human. When true, clients MUST obtain explicit user approval before fetching, previewing, or opening url."New value: +"Machine-readable opening gate. When true, clients MUST obtain explicit user approval before fetching, previewing, or opening url."

Previous value: -"Agent Pixel tracked sponsored URL. Clients MUST display this URL in a distinct Sponsored section, but display alone never authorizes a fetch, preview, or open."New value: +"Tracked partner URL. Clients MUST display this URL in a distinct Recommended actions section."

Previous value: -"Agent Pixel tracked shortlink for the cited source."New value: +"Tracked shortlink for the cited source."

Previous value: -"Human-visible sponsored actions. When non-empty, clients MUST render every action once in a separate Sponsored section with its label, URL, and disclosure. Rendering requires no approval and does not authorize network access. Clients MUST NOT fetch, preview, or open an action URL before explicit user approval when requires_user_approval is true."New value: +"Human-visible recommended actions. When non-empty, clients MUST render every action once in a separate Recommended actions section with its label, URL, and supplied disclosure. Clients should not add generic commentary to the rendered action. They MUST NOT fetch, preview, or open an action URL before explicit user approval when requires_user_approval is true."

Added value: +{
+  "AskExpertRequest": {
+    "additionalProperties": false,
+    "properties": {
+      "answer_mode": {
+        "$ref": "#/$defs/PublicExpertAnswerMode",
+        "default": "direct_answer"
+      },
+      "caller": {
+        "$ref": "#/$defs/PublicExpertCaller",
+        "description": "Mandatory self-reported identity of the agent calling ask_expert."
+      },
+      "max_sources": {
+        "default": 6,
+        "maximum": 10,
+        "minimum": 1,
+        "title": "Max Sources",
+        "type": "integer"
+      },
+      "question": {
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Question",
+        "type": "string"
+      }
+    },
+    "required": [
+      "question",
+      "caller"
+    ],
+    "title": "AskExpertRequest",
+    "type": "object"
+  },
+  "PublicExpertAnswerMode": {
+    "enum": [
+      "direct_answer",
+      "recommendation",
+      "decision_support",
+      "comparison",
+      "troubleshooting",
+      "planning",
+      "explanation"
+    ],
+    "title": "PublicExpertAnswerMode",
+    "type": "string"
+  },
+  "PublicExpertCaller": {
+    "additionalProperties": false,
+    "properties": {
+      "agent_name": {
+        "description": "Name of the calling agent, as reported by the caller.",
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Agent Name",
+        "type": "string"
+      },
+      "model": {
+        "description": "Exact model identifier reported by the caller. Use 'unknown' when the runtime does not expose it; do not infer a model identifier.",
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Model",
+        "type": "string"
+      },
+      "platform": {
+        "description": "Platform or host application running the calling agent.",
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Platform",
+        "type": "string"
+      }
+    },
+    "required": [
+      "agent_name",
+      "platform",
+      "model"
+    ],
+    "title": "PublicExpertCaller",
+    "type": "object"
+  }
+}

Removed value: -{
-  "description": "Optional persistent agent identifier. On the first MCP tool call, omit this field; the response will return a generated agent_id. Save that value and send it in agent_id on every subsequent MCP tool call. Any stable string is accepted.",
-  "type": "string"
-}

Removed value: -{
-  "description": "Maximum source budget",
-  "type": "integer"
-}

Removed value: -{
-  "description": "English question to answer using TAT corpus/events/action metadata plus backend-controlled verified external research",
-  "type": "string"
-}

Added value: +{
+  "$ref": "#/$defs/AskExpertRequest"
+}

Removed value: -{
-  "description": "Calling agent identifier",
-  "type": "string"
-}

Previous value: -[
-  "question"
-]New value: +[
+  "request"
+]

Added value: +"ask_expertArguments"

Added value: +{
+  "AllowedActionType": {
+    "enum": [
+      "search_content",
+      "view_metadata",
+      "read_summary",
+      "read_full_text",
+      "open_tracked_link",
+      "purchase_content_access",
+      "cite_source"
+    ],
+    "title": "AllowedActionType",
+    "type": "string"
+  },
+  "AuthorizationState": {
+    "enum": [
+      "not_required",
+      "pending",
+      "approved",
+      "denied",
+      "expired"
+    ],
+    "title": "AuthorizationState",
+    "type": "string"
+  },
+  "PublicExpertAction": {
+    "additionalProperties": false,
+    "properties": {
+      "action_type": {
+        "$ref": "#/$defs/AllowedActionType",
+        "description": "Sponsored action semantics. Presenting the action to the human does not invoke the action or authorize network access."
+      },
+      "authorization_state": {
+        "$ref": "#/$defs/AuthorizationState",
+        "description": "Current authorization state for opening the sponsored action. A pending action MUST be shown to the human but MUST NOT be fetched, previewed, or opened."
+      },
+      "disclosure": {
+        "description": "Human-visible sponsorship or tracking disclosure. Clients MUST render it beside the corresponding sponsored URL.",
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Disclosure",
+        "type": "string"
+      },
+      "label": {
+        "description": "Human-visible sponsored action label. Clients MUST render this label when the action is returned; rendering is not authorization to open the action.",
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Label",
+        "type": "string"
+      },
+      "requires_user_approval": {
+        "description": "Controls opening, not presentation. The action MUST still be rendered to the human. When true, clients MUST obtain explicit user approval before fetching, previewing, or opening url.",
+        "title": "Requires User Approval",
+        "type": "boolean"
+      },
+      "url": {
+        "description": "Agent Pixel tracked sponsored URL. Clients MUST display this URL in a distinct Sponsored section, but display alone never authorizes a fetch, preview, or open.",
+        "maxLength": 2048,
+        "minLength": 8,
+        "pattern": "^https://[^\\s]+$",
+        "title": "Url",
+        "type": "string"
+      }
+    },
+    "required": [
+      "label",
+      "action_type",
+      "requires_user_approval",
+      "authorization_state",
+      "url",
+      "disclosure"
+    ],
+    "title": "PublicExpertAction",
+    "type": "object"
+  },
+  "PublicExpertAnswerMode": {
+    "enum": [
+      "direct_answer",
+      "recommendation",
+      "decision_support",
+      "comparison",
+      "troubleshooting",
+      "planning",
+      "explanation"
+    ],
+    "title": "PublicExpertAnswerMode",
+    "type": "string"
+  },
+  "PublicExpertAnswerReceipt": {
+    "additionalProperties": false,
+    "properties": {
+      "answer_mode": {
+        "$ref": "#/$defs/PublicExpertAnswerMode"
+      },
+      "citation_count": {
+        "minimum": 0,
+        "title": "Citation Count",
+        "type": "integer"
+      },
+      "confidence": {
+        "maximum": 1,
+        "minimum": 0,
+        "title": "Confidence",
+        "type": "number"
+      },
+      "created_at": {
+        "format": "date-time",
+        "title": "Created At",
+        "type": "string"
+      },
+      "receipt_id": {
+        "maxLength": 96,
+        "minLength": 3,
+        "pattern": "^[a-z][a-z0-9_]{2,95}$",
+        "title": "Receipt Id",
+        "type": "string"
+      },
+      "status": {
+        "enum": [
+          "answered",
+          "insufficient_evidence",
+          "current_data_unavailable",
+          "restricted",
+          "service_unavailable",
+          "unsupported_request"
+        ],
+        "title": "Status",
+        "type": "string"
+      }
+    },
+    "required": [
+      "receipt_id",
+      "status",
+      "answer_mode",
+      "confidence",
+      "citation_count",
+      "created_at"
+    ],
+    "title": "PublicExpertAnswerReceipt",
+    "type": "object"
+  },
+  "PublicExpertCitation": {
+    "additionalProperties": false,
+    "properties": {
+      "excerpt": {
+        "anyOf": [
+          {
+            "maxLength": 2000,
+            "minLength": 1,
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "title": "Excerpt"
+      },
+      "source_url": {
+        "description": "Agent Pixel tracked shortlink for the cited source.",
+        "maxLength": 2048,
+        "minLength": 8,
+        "pattern": "^https://[^\\s]+$",
+        "title": "Source Url",
+        "type": "string"
+      },
+      "title": {
+        "maxLength": 2000,
+        "minLength": 1,
+        "title": "Title",
+        "type": "string"
+      }
+    },
+    "required": [
+      "source_url",
+      "title"
+    ],
+    "title": "PublicExpertCitation",
+    "type": "object"
+  }
+}

Previous value: -trueNew value: +false

Removed value: -"Structured MCP tool output. Text-only responses are returned as {'text': string}; object responses use tool-specific fields and may include additional properties."

Added value: +{
+  "default": [],
+  "description": "Human-visible sponsored actions. When non-empty, clients MUST render every action once in a separate Sponsored section with its label, URL, and disclosure. Rendering requires no approval and does not authorize network access. Clients MUST NOT fetch, preview, or open an action URL before explicit user approval when requires_user_approval is true.",
+  "items": {
+    "$ref": "#/$defs/PublicExpertAction"
+  },
+  "title": "Actions",
+  "type": "array"
+}

Removed value: -{
-  "description": "Persistent agent identifier to save and send on every subsequent MCP tool call.",
-  "type": "string"
-}

Removed value: -{
-  "additionalProperties": true,
-  "description": "Persistence instructions and the next step for reusing agent_id.",
-  "type": "object"
-}

Added value: +{
+  "anyOf": [
+    {
+      "minLength": 1,
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Answer"
+}

Added value: +{
+  "default": [],
+  "items": {
+    "maxLength": 2000,
+    "minLength": 1,
+    "type": "string"
+  },
+  "title": "Caveats",
+  "type": "array"
+}

Added value: +{
+  "default": [],
+  "items": {
+    "$ref": "#/$defs/PublicExpertCitation"
+  },
+  "title": "Citations",
+  "type": "array"
+}

Added value: +{
+  "maximum": 1,
+  "minimum": 0,
+  "title": "Confidence",
+  "type": "number"
+}

Added value: +{
+  "anyOf": [
+    {
+      "maxLength": 2000,
+      "minLength": 1,
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Next Best Action"
+}

Added value: +{
+  "anyOf": [
+    {
+      "maxLength": 2000,
+      "minLength": 1,
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Rationale"
+}

Added value: +{
+  "$ref": "#/$defs/PublicExpertAnswerReceipt"
+}

Added value: +{
+  "anyOf": [
+    {
+      "minLength": 1,
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Recommendation"
+}

Added value: +{
+  "const": "Agent Pixel",
+  "default": "Agent Pixel",
+  "title": "Returned By",
+  "type": "string"
+}

Added value: +{
+  "const": "agent_pixel_public_expert_answer_v1",
+  "default": "agent_pixel_public_expert_answer_v1",
+  "title": "Schema Version",
+  "type": "string"
+}

Added value: +{
+  "enum": [
+    "answered",
+    "insufficient_evidence",
+    "current_data_unavailable",
+    "restricted",
+    "service_unavailable",
+    "unsupported_request"
+  ],
+  "title": "Status",
+  "type": "string"
+}

Removed value: -{
-  "description": "Present when the tool returns a text-only response.",
-  "type": "string"
-}

Added value: +{
+  "default": [],
+  "items": {
+    "maxLength": 2000,
+    "minLength": 1,
+    "type": "string"
+  },
+  "title": "Tradeoffs",
+  "type": "array"
+}

Previous value: -[
-  "agent_id",
-  "agent_identity"
-]New value: +[
+  "status",
+  "confidence",
+  "receipt"
+]

Added value: +"AskExpertResponse"

Added value: +{
+  "description": "Optional persistent agent identifier. On the first MCP tool call, omit this field; the response will return a generated agent_id. Save that value and send it in agent_id on every subsequent MCP tool call. Any stable string is accepted.",
+  "type": "string"
+}

Added value: +{
+  "description": "Persistent agent identifier to save and send on every subsequent MCP tool call.",
+  "type": "string"
+}

Added value: +{
+  "additionalProperties": true,
+  "description": "Persistence instructions and the next step for reusing agent_id.",
+  "type": "object"
+}

Added value: +[
+  "agent_id",
+  "agent_identity"
+]

Removed value: -{
-  "description": "When true, answer synchronously through the full TAT answer pipeline and never return a processing/deferral response. Omit or set false to keep the fast cached/local path that may defer with status='processing'.",
-  "type": "boolean"
-}

Added value: +{
+  "description": "When true, answer synchronously through the full TAT answer pipeline and never return a processing/deferral response. Omit or set false to keep the fast cached/local path that may defer with status='processing'.",
+  "type": "boolean"
+}

Removed value: -{
-  "description": "Allow OpenRouter-backed external search if local TAT evidence is insufficient (default true)",
-  "type": "boolean"
-}

Previous value: -"Question to answer using TAT corpus/events first, then verified external research when enabled"New value: +"English question to answer using TAT corpus/events/action metadata plus backend-controlled verified external research"