apply change to all versions.

specification/ai/Azure.AI.Agents/run_steps/models.tsp

@@ -106,7 +106,6 @@ union RunStepType {
   toolCalls: "tool_calls",
 
   @doc("Represents a run step with activities information.")
-  @added(Versions.v2025_05_15_preview)
   activities: "activities",
 }
 
@@ -149,7 +148,6 @@ model RunStepMessageCreationReference {
 }
 
 @doc("The detailed information associated with a run step activities.")
-@added(Versions.v2025_05_15_preview)
 model RunStepActivityDetails extends RunStepDetails {
   @doc("The object type, which is always 'activities'.")
   type: RunStepType.activities;
@@ -481,8 +479,7 @@ union RunAdditionalFieldList {
   FileSearchContents: "step_details.tool_calls[*].file_search.results[*].content",
 }
 
-/** Represents the list of activities, associated with the given step.* */
-@added(Versions.v2025_05_15_preview)
+/** Represents the list of activities, associated with the given step. */
 model RunStepDetailsActivity {
   @doc("The activity type, which is always 'mcp_list_tools'.")
   type: "mcp_list_tools";
@@ -499,7 +496,6 @@ model RunStepDetailsActivity {
 }
 
 @doc("The activity definition information for a function.")
-@added(Versions.v2025_05_15_preview)
 model ActivityFunctionDefinition {
   @doc("A description of what the function does, used by the model to choose when and how to call the function.")
   description?: string;
@@ -509,7 +505,6 @@ model ActivityFunctionDefinition {
 }
 
 @doc("The parameters used for activity function definition.")
-@added(Versions.v2025_05_15_preview)
 model ActivityFunctionParameters {
   @doc("The parameter type, it is always object.")
   type: "object";
@@ -525,7 +520,6 @@ model ActivityFunctionParameters {
 }
 
 @doc("The function argument and description.")
-@added(Versions.v2025_05_15_preview)
 model FunctionArgument {
   @doc("The type of an argument, for example 'string' or 'number'.")
   type: string;

specification/ai/data-plane/Azure.AI.Agents/preview/2025-05-15-preview/azure-ai-agents.json

@@ -7118,7 +7118,7 @@
     },
     "RunStepDetailsActivity": {
       "type": "object",
-      "description": "Represents the list of activities, associated with the given step.*",
+      "description": "Represents the list of activities, associated with the given step.",
       "properties": {
         "type": {
           "type": "string",

specification/ai/data-plane/Azure.AI.Agents/stable/2025-05-01/azure-ai-agents.json

@@ -2754,6 +2754,62 @@
         }
       }
     },
+    "ActivityFunctionDefinition": {
+      "type": "object",
+      "description": "The activity definition information for a function.",
+      "properties": {
+        "description": {
+          "type": "string",
+          "description": "A description of what the function does, used by the model to choose when and how to call the function."
+        },
+        "parameters": {
+          "$ref": "#/definitions/ActivityFunctionParameters",
+          "description": "The parameters the functions accepts, described as a JSON Schema object."
+        }
+      },
+      "required": [
+        "parameters"
+      ]
+    },
+    "ActivityFunctionParameters": {
+      "type": "object",
+      "description": "The parameters used for activity function definition.",
+      "properties": {
+        "type": {
+          "type": "string",
+          "description": "The parameter type, it is always object.",
+          "enum": [
+            "object"
+          ],
+          "x-ms-enum": {
+            "modelAsString": false
+          }
+        },
+        "properties": {
+          "type": "object",
+          "description": "The dictionary of function arguments.",
+          "additionalProperties": {
+            "$ref": "#/definitions/FunctionArgument"
+          }
+        },
+        "required": {
+          "type": "array",
+          "description": "The list of the required parameters.",
+          "items": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": {
+          "type": "boolean",
+          "description": "If true the function has additional parameters."
+        }
+      },
+      "required": [
+        "type",
+        "properties",
+        "required"
+      ]
+    },
     "Agent": {
       "type": "object",
       "description": "Represents an agent that can call the model and use tools.",
@@ -4277,6 +4333,23 @@
         ]
       }
     },
+    "FunctionArgument": {
+      "type": "object",
+      "description": "The function argument and description.",
+      "properties": {
+        "type": {
+          "type": "string",
+          "description": "The type of an argument, for example 'string' or 'number'."
+        },
+        "description": {
+          "type": "string",
+          "description": "The argument description."
+        }
+      },
+      "required": [
+        "type"
+      ]
+    },
     "FunctionDefinition": {
       "type": "object",
       "description": "The input definition information for a function.",
@@ -5858,6 +5931,28 @@
         "metadata"
       ]
     },
+    "RunStepActivityDetails": {
+      "type": "object",
+      "description": "The detailed information associated with a run step activities.",
+      "properties": {
+        "activities": {
+          "type": "array",
+          "description": "A list of activities for this run step.",
+          "items": {
+            "$ref": "#/definitions/RunStepDetailsActivity"
+          }
+        }
+      },
+      "required": [
+        "activities"
+      ],
+      "allOf": [
+        {
+          "$ref": "#/definitions/RunStepDetails"
+        }
+      ],
+      "x-ms-discriminator-value": "activities"
+    },
     "RunStepAzureAISearchToolCall": {
       "type": "object",
       "description": "A record of a call to an Azure AI Search tool, issued by the model in evaluation of a defined tool, that represents\nexecuted Azure AI search.",
@@ -6330,6 +6425,44 @@
         "type"
       ]
     },
+    "RunStepDetailsActivity": {
+      "type": "object",
+      "description": "Represents the list of activities, associated with the given step.",
+      "properties": {
+        "type": {
+          "type": "string",
+          "description": "The activity type, which is always 'mcp_list_tools'.",
+          "enum": [
+            "mcp_list_tools"
+          ],
+          "x-ms-enum": {
+            "modelAsString": false
+          }
+        },
+        "id": {
+          "type": "string",
+          "description": "The activity ID."
+        },
+        "server_label": {
+          "type": "string",
+          "description": "Server label.",
+          "x-ms-client-name": "serverLabel"
+        },
+        "tools": {
+          "type": "object",
+          "description": "The supported function list.",
+          "additionalProperties": {
+            "$ref": "#/definitions/ActivityFunctionDefinition"
+          }
+        }
+      },
+      "required": [
+        "type",
+        "id",
+        "server_label",
+        "tools"
+      ]
+    },
     "RunStepError": {
       "type": "object",
       "description": "The error information associated with a failed run step.",
@@ -6690,7 +6823,8 @@
       "description": "The possible types of run steps.",
       "enum": [
         "message_creation",
-        "tool_calls"
+        "tool_calls",
+        "activities"
       ],
       "x-ms-enum": {
         "name": "RunStepType",
@@ -6705,6 +6839,11 @@
             "name": "toolCalls",
             "value": "tool_calls",
             "description": "Represents a run step that calls tools."
+          },
+          {
+            "name": "activities",
+            "value": "activities",
+            "description": "Represents a run step with activities information."
           }
         ]
       }