Python: Updates to Tools (#1835)

* updated tool samples

* mypy and readme fixes

* updated call logic

* added function invocation config

* added include detailed error

* added tests

* updated FRC exception handling

* updated tests

* fix oai test

* fix name in sample

* imporoved tests coverage and removed some dead code paths

python/packages/core/tests/core/test_tools.py

@@ -63,6 +63,26 @@ def test_ai_function_decorator_without_args():
     assert test_tool(1, 2) == 3
 
 
+def test_ai_function_without_args():
+    """Test the ai_function decorator."""
+
+    @ai_function
+    def test_tool() -> int:
+        """A simple function that adds two numbers."""
+        return 1 + 2
+
+    assert isinstance(test_tool, ToolProtocol)
+    assert isinstance(test_tool, AIFunction)
+    assert test_tool.name == "test_tool"
+    assert test_tool.description == "A simple function that adds two numbers."
+    assert test_tool.parameters() == {
+        "properties": {},
+        "title": "test_tool_input",
+        "type": "object",
+    }
+    assert test_tool() == 3
+
+
 async def test_ai_function_decorator_with_async():
     """Test the ai_function decorator with an async function."""
 

python/packages/core/tests/openai/test_openai_chat_client.py

@@ -689,12 +689,15 @@ def test_function_result_exception_handling(openai_unit_test_env: dict[str, str]
     # Test with exception (no result)
     test_exception = ValueError("Test error message")
     message_with_exception = ChatMessage(
-        role="tool", contents=[FunctionResultContent(call_id="call-123", exception=test_exception)]
+        role="tool",
+        contents=[
+            FunctionResultContent(call_id="call-123", result="Error: Function failed.", exception=test_exception)
+        ],
     )
 
     openai_messages = client._openai_chat_message_parser(message_with_exception)
     assert len(openai_messages) == 1
-    assert openai_messages[0]["content"] == "Error: Test error message"
+    assert openai_messages[0]["content"] == "Error: Function failed."
     assert openai_messages[0]["tool_call_id"] == "call-123"