[bug] Validates If The Role Tool is Handled Correctly after Transforms (

#3875)

autogen/agentchat/contrib/capabilities/transforms.py

@@ -102,6 +102,9 @@ def apply_transform(self, messages: List[Dict]) -> List[Dict]:
             if remaining_count == 0:
                 break
 
+        if not transforms_util.is_tool_call_valid(truncated_messages):
+            truncated_messages.pop()
+
         return truncated_messages
 
     def get_logs(self, pre_transform_messages: List[Dict], post_transform_messages: List[Dict]) -> Tuple[str, bool]:
@@ -229,6 +232,9 @@ def apply_transform(self, messages: List[Dict]) -> List[Dict]:
             processed_messages_tokens += msg_tokens
             processed_messages.insert(0, msg)
 
+        if not transforms_util.is_tool_call_valid(processed_messages):
+            processed_messages.pop()
+
         return processed_messages
 
     def get_logs(self, pre_transform_messages: List[Dict], post_transform_messages: List[Dict]) -> Tuple[str, bool]:

autogen/agentchat/contrib/capabilities/transforms_util.py

@@ -112,3 +112,7 @@ def should_transform_message(message: Dict[str, Any], filter_dict: Optional[Dict
         return True
 
     return len(filter_config([message], filter_dict, exclude)) > 0
+
+
+def is_tool_call_valid(messages: List[Dict[str, Any]]) -> bool:
+    return messages[0].get("role") != "tool"