diff --git a/python/packages/azure-ai/agent_framework_azure_ai/_client.py b/python/packages/azure-ai/agent_framework_azure_ai/_client.py
index 774349a85d..2fa54ea565 100644
--- a/python/packages/azure-ai/agent_framework_azure_ai/_client.py
+++ b/python/packages/azure-ai/agent_framework_azure_ai/_client.py
@@ -73,7 +73,7 @@ def __init__(
 
         Keyword Args:
             project_client: An existing AIProjectClient to use. If not provided, one will be created.
-            agent_name: The name to use when creating new agents.
+            agent_name: The name to use when creating new agents or using existing agents.
             agent_version: The version of the agent to use.
             conversation_id: Default conversation ID to use for conversations. Can be overridden by
                 conversation_id property when making a request.
@@ -194,17 +194,21 @@ async def _get_agent_reference_or_create(
         """Determine which agent to use and create if needed.
 
         Returns:
-            str: The agent_name to use
+            dict[str, str]: The agent reference to use.
         """
-        agent_name = self.agent_name or "UnnamedAgent"
+        # Agent name must be explicitly provided by the user.
+        if self.agent_name is None:
+            raise ServiceInitializationError(
+                "Agent name is required. Provide 'agent_name' when initializing AzureAIClient "
+                "or 'name' when initializing ChatAgent."
+            )
 
         # If no agent_version is provided, either use latest version or create a new agent:
         if self.agent_version is None:
             # Try to use latest version if requested and agent exists
             if self.use_latest_version:
                 try:
-                    existing_agent = await self.project_client.agents.get(agent_name)
-                    self.agent_name = existing_agent.name
+                    existing_agent = await self.project_client.agents.get(self.agent_name)
                     self.agent_version = existing_agent.versions.latest.version
                     return {"name": self.agent_name, "version": self.agent_version, "type": "agent_reference"}
                 except ResourceNotFoundError:
@@ -241,13 +245,12 @@ async def _get_agent_reference_or_create(
                 args["instructions"] = "".join(combined_instructions)
 
             created_agent = await self.project_client.agents.create_version(
-                agent_name=agent_name, definition=PromptAgentDefinition(**args)
+                agent_name=self.agent_name, definition=PromptAgentDefinition(**args)
             )
 
-            self.agent_name = created_agent.name
             self.agent_version = created_agent.version
 
-        return {"name": agent_name, "version": self.agent_version, "type": "agent_reference"}
+        return {"name": self.agent_name, "version": self.agent_version, "type": "agent_reference"}
 
     async def _close_client_if_needed(self) -> None:
         """Close project_client session if we created it."""
@@ -276,6 +279,7 @@ def _prepare_input(self, messages: MutableSequence[ChatMessage]) -> tuple[list[C
     async def prepare_options(
         self, messages: MutableSequence[ChatMessage], chat_options: ChatOptions
     ) -> dict[str, Any]:
+        """Take ChatOptions and create the specific options for Azure AI."""
         chat_options.store = bool(chat_options.store or chat_options.store is None)
         prepared_messages, instructions = self._prepare_input(messages)
         run_options = await super().prepare_options(prepared_messages, chat_options)
diff --git a/python/packages/azure-ai/tests/test_azure_ai_client.py b/python/packages/azure-ai/tests/test_azure_ai_client.py
index 576218f270..ead970785d 100644
--- a/python/packages/azure-ai/tests/test_azure_ai_client.py
+++ b/python/packages/azure-ai/tests/test_azure_ai_client.py
@@ -161,6 +161,16 @@ async def test_azure_ai_client_get_agent_reference_or_create_existing_version(
     assert agent_ref == {"name": "existing-agent", "version": "1.0", "type": "agent_reference"}
 
 
+async def test_azure_ai_client_get_agent_reference_or_create_missing_agent_name(
+    mock_project_client: MagicMock,
+) -> None:
+    """Test _get_agent_reference_or_create raises when agent_name is missing."""
+    client = create_test_azure_ai_client(mock_project_client, agent_name=None)
+
+    with pytest.raises(ServiceInitializationError, match="Agent name is required"):
+        await client._get_agent_reference_or_create({}, None)  # type: ignore
+
+
 async def test_azure_ai_client_get_agent_reference_or_create_new_agent(
     mock_project_client: MagicMock,
     azure_ai_unit_test_env: dict[str, str],
diff --git a/python/samples/getting_started/agents/azure_ai/azure_ai_with_code_interpreter.py b/python/samples/getting_started/agents/azure_ai/azure_ai_with_code_interpreter.py
index a2ea4aafe3..b81a2add85 100644
--- a/python/samples/getting_started/agents/azure_ai/azure_ai_with_code_interpreter.py
+++ b/python/samples/getting_started/agents/azure_ai/azure_ai_with_code_interpreter.py
@@ -22,6 +22,7 @@ async def main() -> None:
     async with (
         AzureCliCredential() as credential,
         AzureAIClient(async_credential=credential).create_agent(
+            name="MyCodeInterpreterAgent",
             instructions="You are a helpful assistant that can write and execute Python code to solve problems.",
             tools=HostedCodeInterpreterTool(),
         ) as agent,