diff --git a/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud.py b/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud.py
index 62f7eb302cc2..91b9f3e77529 100644
--- a/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud.py
+++ b/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud.py
@@ -6,6 +6,7 @@
 # cSpell:disable
 import json
 import io
+import openai
 from test_base import TestBase, servicePreparer
 from devtools_testutils import recorded_by_proxy, RecordedTransport
 from azure.ai.projects.models import PromptAgentDefinition, AgentDetails, AgentVersionDetails
@@ -141,7 +142,15 @@ def test_agent_disable_enable(self, **kwargs):
 
         # Setup
         project_client = self.create_client(operation_group="agents", **kwargs)
-        openai_client = project_client.get_openai_client()
+        # Intentionally use Agent Endpoint here for Responses calls (by giving `agent_name`). Async tests will use Project
+        # endpoint instead, so we cover both endpoint.
+        openai_client = project_client.get_openai_client(agent_name=agent_name)
+
+        # Delete any existing agent from previous test runs (ignore failures)
+        try:
+            project_client.agents.delete(agent_name=agent_name)
+        except Exception:
+            pass
 
         # Create an Agent
         agent = project_client.agents.create_version(
@@ -173,17 +182,16 @@ def test_agent_disable_enable(self, **kwargs):
         print(f"Agent disabled")
 
         # Verify requests fail when agent is disabled
-        # TODO: Why does this call succeed, even though the Agent is disabled?
-        # error_raised = False
-        # try:
-        #     _ = openai_client.responses.create(
-        #         conversation=conversation.id,
-        #         extra_body={"agent_reference": {"name": agent.name, "type": "agent_reference"}},
-        #     )
-        # except Exception as e:
-        #     error_raised = True
-        #     print(f"Expected error when calling disabled agent: {e}")
-        # assert error_raised, "Expected an error when calling a disabled agent"
+        error_raised = False
+        try:
+            _ = openai_client.responses.create(
+                conversation=conversation.id,
+                extra_body={"agent_reference": {"name": agent.name, "type": "agent_reference"}},
+            )
+        except openai.PermissionDeniedError as e:
+            error_raised = True
+            print(f"Expected error when calling disabled agent: {e}")
+        assert error_raised, "Expected an error when calling a disabled agent"
 
         # Enable the agent
         project_client.agents.enable(agent_name=agent_name)
diff --git a/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud_async.py b/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud_async.py
index c66100031aa9..82c32a4b9ebc 100644
--- a/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud_async.py
+++ b/sdk/ai/azure-ai-projects/tests/agents/test_agents_crud_async.py
@@ -6,6 +6,7 @@
 # cSpell:disable
 import json
 import io
+import openai
 from test_base import TestBase, servicePreparer
 from devtools_testutils.aio import recorded_by_proxy_async
 from devtools_testutils import RecordedTransport
@@ -131,9 +132,18 @@ async def test_agent_disable_enable_async(self, **kwargs):
 
         # Setup
         project_client = self.create_async_client(operation_group="agents", **kwargs)
+        # Intentionally use Project Endpoint here for Responses calls (by not giving `agent_name`). Sync tests will use Agent
+        # endpoint instead, so we cover both endpoint.
         openai_client = project_client.get_openai_client()
 
         async with project_client:
+
+            # Delete any existing agent from previous test runs (ignore failures)
+            try:
+                await project_client.agents.delete(agent_name=agent_name)
+            except Exception:
+                pass
+
             # Create an Agent
             agent = await project_client.agents.create_version(
                 agent_name=agent_name,
@@ -164,17 +174,16 @@ async def test_agent_disable_enable_async(self, **kwargs):
             print("Agent disabled")
 
             # Verify requests fail when agent is disabled
-            # TODO: Why does this call succeed, even though the Agent is disabled?
-            # error_raised = False
-            # try:
-            #     _ = await openai_client.responses.create(
-            #         conversation=conversation.id,
-            #         extra_body={"agent_reference": {"name": agent.name, "type": "agent_reference"}},
-            #     )
-            # except Exception as e:
-            #     error_raised = True
-            #     print(f"Expected error when calling disabled agent: {e}")
-            # assert error_raised, "Expected an error when calling a disabled agent"
+            error_raised = False
+            try:
+                _ = await openai_client.responses.create(
+                    conversation=conversation.id,
+                    extra_body={"agent_reference": {"name": agent.name, "type": "agent_reference"}},
+                )
+            except openai.PermissionDeniedError as e:
+                error_raised = True
+                print(f"Expected error when calling disabled agent: {e}")
+            assert error_raised, "Expected an error when calling a disabled agent"
 
             # Enable the agent
             await project_client.agents.enable(agent_name=agent_name)