diff --git a/autogen/agentchat/conversable_agent.py b/autogen/agentchat/conversable_agent.py
index d2f8763281..840da79204 100644
--- a/autogen/agentchat/conversable_agent.py
+++ b/autogen/agentchat/conversable_agent.py
@@ -659,6 +659,9 @@ def _append_oai_message(self, message: Union[Dict, str], role, conversation_id:
 
         if message.get("role") in ["function", "tool"]:
             oai_message["role"] = message.get("role")
+            if "tool_responses" in oai_message:
+                for tool_response in oai_message["tool_responses"]:
+                    tool_response["content"] = str(tool_response["content"])
         elif "override_role" in message:
             # If we have a direction to override the role then set the
             # role accordingly. Used to customise the role for the
@@ -791,15 +794,16 @@ async def a_send(
                 "Message can't be converted into a valid ChatCompletion message. Either content or function_call must be provided."
             )
 
-    def _print_received_message(self, message: Union[Dict, str], sender: Agent):
+    def _print_received_message(self, message: Union[Dict, str], sender: Agent, skip_head: bool = False):
         iostream = IOStream.get_default()
         # print the message received
-        iostream.print(colored(sender.name, "yellow"), "(to", f"{self.name}):\n", flush=True)
+        if not skip_head:
+            iostream.print(colored(sender.name, "yellow"), "(to", f"{self.name}):\n", flush=True)
         message = self._message_to_dict(message)
 
         if message.get("tool_responses"):  # Handle tool multi-call responses
             for tool_response in message["tool_responses"]:
-                self._print_received_message(tool_response, sender)
+                self._print_received_message(tool_response, sender, skip_head=True)
             if message.get("role") == "tool":
                 return  # If role is tool, then content is just a concatenation of all tool_responses
 
@@ -2288,7 +2292,7 @@ def _format_json_str(jstr):
             result.append(char)
         return "".join(result)
 
-    def execute_function(self, func_call, verbose: bool = False) -> Tuple[bool, Dict[str, str]]:
+    def execute_function(self, func_call, verbose: bool = False) -> Tuple[bool, Dict[str, Any]]:
         """Execute a function call and return the result.
 
         Override this function to modify the way to execute function and tool calls.
@@ -2342,7 +2346,7 @@ def execute_function(self, func_call, verbose: bool = False) -> Tuple[bool, Dict
         return is_exec_success, {
             "name": func_name,
             "role": "function",
-            "content": str(content),
+            "content": content,
         }
 
     async def a_execute_function(self, func_call):
@@ -2397,7 +2401,7 @@ async def a_execute_function(self, func_call):
         return is_exec_success, {
             "name": func_name,
             "role": "function",
-            "content": str(content),
+            "content": content,
         }
 
     def generate_init_message(self, message: Union[Dict, str, None], **kwargs) -> Union[str, Dict]:
diff --git a/autogen/agentchat/groupchat.py b/autogen/agentchat/groupchat.py
index 4e9e107f92..0e14bf35f8 100644
--- a/autogen/agentchat/groupchat.py
+++ b/autogen/agentchat/groupchat.py
@@ -294,6 +294,8 @@ def append(self, message: Dict, speaker: Agent):
         # if the role is tool, it is OK to modify the name
         if message["role"] != "function":
             message["name"] = speaker.name
+        if not isinstance(message["content"], str) and not isinstance(message["content"], list):
+            message["content"] = str(message["content"])
         message["content"] = content_str(message["content"])
         self.messages.append(message)
 
diff --git a/test/agentchat/test_conversable_agent.py b/test/agentchat/test_conversable_agent.py
index 8790c84db1..81e0036dc0 100755
--- a/test/agentchat/test_conversable_agent.py
+++ b/test/agentchat/test_conversable_agent.py
@@ -464,14 +464,14 @@ def add_num(num_to_be_added):
 
     # when sender is None, messages is provided
     assert (
-        dummy_agent_2.generate_reply(messages=messages, sender=None)["content"] == "15"
+        dummy_agent_2.generate_reply(messages=messages, sender=None)["content"] == 15
     ), "generate_reply not working when sender is None"
 
     # when sender is provided, messages is None
     dummy_agent_1 = ConversableAgent(name="dummy_agent_1", llm_config=False, human_input_mode="ALWAYS")
     dummy_agent_2._oai_messages[dummy_agent_1] = messages
     assert (
-        dummy_agent_2.generate_reply(messages=None, sender=dummy_agent_1)["content"] == "15"
+        dummy_agent_2.generate_reply(messages=None, sender=dummy_agent_1)["content"] == 15
     ), "generate_reply not working when messages is None"
 
     dummy_agent_2.register_reply(["str", None], ConversableAgent.generate_oai_reply)
@@ -1115,7 +1115,7 @@ class Function:
 
         def get_random_number(self):
             self.call_count += 1
-            return random.randint(0, 100)
+            return str(random.randint(0, 100))
 
     config_list = autogen.config_list_from_json(
         OAI_CONFIG_LIST,
@@ -1171,7 +1171,7 @@ class Function:
 
         def get_random_number(self):
             self.call_count += 1
-            return random.randint(0, 100)
+            return str(random.randint(0, 100))
 
     config_list = autogen.config_list_from_json(
         OAI_CONFIG_LIST, file_location=KEY_LOC, filter_dict={"tags": ["gpt-3.5-turbo"]}
diff --git a/test/agentchat/test_function_call.py b/test/agentchat/test_function_call.py
index 525a24cc17..5dfcd839f3 100755
--- a/test/agentchat/test_function_call.py
+++ b/test/agentchat/test_function_call.py
@@ -110,7 +110,7 @@ def test_execute_function():
     # 1. test calling a simple function
     def add_num(num_to_be_added):
         given_num = 10
-        return num_to_be_added + given_num
+        return str(num_to_be_added + given_num)
 
     user = UserProxyAgent(name="test", function_map={"add_num": add_num})
 
@@ -140,7 +140,7 @@ def __init__(self, given_num):
 
         def add(self, num_to_be_added):
             self.given_num = num_to_be_added + self.given_num
-            return self.given_num
+            return str(self.given_num)
 
     user = UserProxyAgent(name="test", function_map={"add_num": AddNum(given_num=10).add})
     func_call = {"name": "add_num", "arguments": '{ "num_to_be_added": 5 }'}
@@ -149,7 +149,7 @@ def add(self, num_to_be_added):
 
     # 3. test calling a function with no arguments
     def get_number():
-        return 42
+        return str(42)
 
     user = UserProxyAgent("user", function_map={"get_number": get_number})
     func_call = {"name": "get_number", "arguments": "{}"}
@@ -179,7 +179,7 @@ async def test_a_execute_function():
     async def add_num(num_to_be_added):
         given_num = 10
         time.sleep(1)
-        return num_to_be_added + given_num
+        return str(num_to_be_added + given_num)
 
     user = UserProxyAgent(name="test", function_map={"add_num": add_num})
     correct_args = {"name": "add_num", "arguments": '{ "num_to_be_added": 5 }'}
@@ -214,7 +214,7 @@ def __init__(self, given_num):
 
         def add(self, num_to_be_added):
             self.given_num = num_to_be_added + self.given_num
-            return self.given_num
+            return str(self.given_num)
 
     user = UserProxyAgent(name="test", function_map={"add_num": AddNum(given_num=10).add})
     func_call = {"name": "add_num", "arguments": '{ "num_to_be_added": 5 }'}
@@ -223,7 +223,7 @@ def add(self, num_to_be_added):
 
     # 3. test calling a function with no arguments
     def get_number():
-        return 42
+        return str(42)
 
     user = UserProxyAgent("user", function_map={"get_number": get_number})
     func_call = {"name": "get_number", "arguments": "{}"}