feat: update_workflow bug

Author: ai-business-hql

backend/service/workflow_rewrite_agent.py

@@ -102,7 +102,7 @@ def create_workflow_rewrite_agent():
         **Tool Usage Guidelines:**
             - get_current_workflow(): Get current workflow from checkpoint or session
             - remove_node(): Use for incompatible or problematic nodes
-            - update_workflow(): Use to save your changes (ALWAYS call this after you have made changes)
+            - update_workflow(): Use to save your changes (ALWAYS call this after you have made changes), you MUST pass argument `workflow_data` containing the FULL workflow JSON (as a JSON object or a JSON string). Never call `update_workflow` without `workflow_data`.
             - get_node_info(): Get detailed node information and verify input/output types before connecting
 
       

backend/service/workflow_rewrite_tools.py

@@ -126,7 +126,7 @@ def tool_error_function(ctx: RunContextWrapper[Any], error: Exception) -> str:
 
 # def update_workflow(session_id: str, workflow_data: Union[Dict[str, Any], str]) -> str:
 @function_tool
-def update_workflow(workflow_data: str) -> str:
+def update_workflow(workflow_data: str = "") -> str:
     """
     更新当前session的工作流数据
 
@@ -141,6 +141,12 @@ def update_workflow(workflow_data: str) -> str:
         if not session_id:
             return json.dumps({"error": "No session_id found in context"})
 
+        if not workflow_data or not isinstance(workflow_data, str) or not workflow_data.strip():
+            return json.dumps({
+                "error": "Missing required argument: workflow_data",
+                "hint": "Pass the full workflow JSON as a string."
+            })
+        
         log.info(f"[update_workflow] workflow_data: {workflow_data}")
         # 在修改前保存checkpoint
         checkpoint_id = save_checkpoint_before_modification(session_id, "workflow update")