diff --git a/autogen/agentchat/conversable_agent.py b/autogen/agentchat/conversable_agent.py
index 674c8b9248d7..2d8958f3282d 100644
--- a/autogen/agentchat/conversable_agent.py
+++ b/autogen/agentchat/conversable_agent.py
@@ -2234,7 +2234,7 @@ def execute_function(self, func_call, verbose: bool = False) -> Tuple[bool, Dict
                 arguments = json.loads(input_string)
             except json.JSONDecodeError as e:
                 arguments = None
-                content = f"Error: {e}\n You argument should follow json format."
+                content = f"Error: {e}\n The argument must be in JSON format."
 
             # Try to execute the function
             if arguments is not None:
@@ -2291,7 +2291,7 @@ async def a_execute_function(self, func_call):
                 arguments = json.loads(input_string)
             except json.JSONDecodeError as e:
                 arguments = None
-                content = f"Error: {e}\n You argument should follow json format."
+                content = f"Error: {e}\n The argument must be in JSON format."
 
             # Try to execute the function
             if arguments is not None:
diff --git a/test/agentchat/test_function_and_tool_calling.py b/test/agentchat/test_function_and_tool_calling.py
index 893fbe351203..4e0775d014c0 100644
--- a/test/agentchat/test_function_and_tool_calling.py
+++ b/test/agentchat/test_function_and_tool_calling.py
@@ -94,11 +94,11 @@ async def _a_tool_func_error(arg1: str, arg2: str) -> str:
         {
             "tool_call_id": "1",
             "role": "tool",
-            "content": "Error: Expecting property name enclosed in double quotes: line 1 column 37 (char 36)\n You argument should follow json format.",
+            "content": "Error: Expecting property name enclosed in double quotes: line 1 column 37 (char 36)\n The argument must be in JSON format.",
         },
         {"tool_call_id": "2", "role": "tool", "content": "_tool_func_2: value3 value4"},
     ],
-    "content": "Error: Expecting property name enclosed in double quotes: line 1 column 37 (char 36)\n You argument should follow json format.\n\n_tool_func_2: value3 value4",
+    "content": "Error: Expecting property name enclosed in double quotes: line 1 column 37 (char 36)\n The argument must be in JSON format.\n\n_tool_func_2: value3 value4",
 }
 
 _tool_use_message_1_error_expected_reply = {
@@ -154,7 +154,7 @@ async def _a_tool_func_error(arg1: str, arg2: str) -> str:
 _function_use_message_1_bad_json_expected_reply = {
     "name": "_tool_func_1",
     "role": "function",
-    "content": "Error: Expecting property name enclosed in double quotes: line 1 column 37 (char 36)\n You argument should follow json format.",
+    "content": "Error: Expecting property name enclosed in double quotes: line 1 column 37 (char 36)\n The argument must be in JSON format.",
 }
 
 _function_use_message_1_error_expected_reply = {
diff --git a/test/agentchat/test_function_call.py b/test/agentchat/test_function_call.py
index 0f1d4f909426..7023a709d3c1 100755
--- a/test/agentchat/test_function_call.py
+++ b/test/agentchat/test_function_call.py
@@ -115,7 +115,7 @@ def add_num(num_to_be_added):
         "name": "add_num",
         "arguments": '{ "num_to_be_added": 5, given_num: 10 }',
     }  # should be "given_num" with quotes
-    assert "You argument should follow json format." in user.execute_function(func_call=wrong_json_format)[1]["content"]
+    assert "The argument must be in JSON format." in user.execute_function(func_call=wrong_json_format)[1]["content"]
 
     # function execution error with wrong arguments passed
     wrong_args = {"name": "add_num", "arguments": '{ "num_to_be_added": 5, "given_num": 10 }'}
@@ -174,7 +174,7 @@ async def add_num(num_to_be_added):
         "arguments": '{ "num_to_be_added": 5, given_num: 10 }',
     }  # should be "given_num" with quotes
     assert (
-        "You argument should follow json format."
+        "The argument must be in JSON format."
         in (await user.a_execute_function(func_call=wrong_json_format))[1]["content"]
     )