diff --git a/api/core/agent/agent/multi_dataset_router_agent.py b/api/core/agent/agent/multi_dataset_router_agent.py
index 57f054f7f4..5636d91b51 100644
--- a/api/core/agent/agent/multi_dataset_router_agent.py
+++ b/api/core/agent/agent/multi_dataset_router_agent.py
@@ -79,6 +79,8 @@ class MultiDatasetRouterAgent(OpenAIFunctionsAgent):
                 if isinstance(tool_inputs, dict) and 'query' in tool_inputs:
                     tool_inputs['query'] = kwargs['input']
                     agent_decision.tool_input = tool_inputs
+            else:
+                agent_decision.return_values['output'] = ''
             return agent_decision
         except Exception as e:
             new_exception = self.model_instance.handle_exceptions(e)
diff --git a/api/core/agent/agent/structed_multi_dataset_router_agent.py b/api/core/agent/agent/structed_multi_dataset_router_agent.py
index 6b2889f45a..0ba774a88f 100644
--- a/api/core/agent/agent/structed_multi_dataset_router_agent.py
+++ b/api/core/agent/agent/structed_multi_dataset_router_agent.py
@@ -107,6 +107,8 @@ class StructuredMultiDatasetRouterAgent(StructuredChatAgent):
                 if isinstance(tool_inputs, dict) and 'query' in tool_inputs:
                     tool_inputs['query'] = kwargs['input']
                     agent_decision.tool_input = tool_inputs
+            else:
+                agent_decision.return_values['output'] = ''
             return agent_decision
         except OutputParserException:
             return AgentFinish({"output": "I'm sorry, the answer of model is invalid, "