fix agent putout the output of workflow-tool twice (#26835) (#27087)

Author: redSun64

api/core/tools/__base/tool.py

@@ -210,12 +210,13 @@ def create_blob_message(self, blob: bytes, meta: dict | None = None) -> ToolInvo
             meta=meta,
         )
 
-    def create_json_message(self, object: dict) -> ToolInvokeMessage:
+    def create_json_message(self, object: dict, suppress_output: bool = False) -> ToolInvokeMessage:
         """
         create a json message
         """
         return ToolInvokeMessage(
-            type=ToolInvokeMessage.MessageType.JSON, message=ToolInvokeMessage.JsonMessage(json_object=object)
+            type=ToolInvokeMessage.MessageType.JSON,
+            message=ToolInvokeMessage.JsonMessage(json_object=object, suppress_output=suppress_output),
         )
 
     def create_variable_message(

api/core/tools/entities/tool_entities.py

@@ -129,6 +129,7 @@ class TextMessage(BaseModel):
 
     class JsonMessage(BaseModel):
         json_object: dict
+        suppress_output: bool = Field(default=False, description="Whether to suppress JSON output in result string")
 
     class BlobMessage(BaseModel):
         blob: bytes

api/core/tools/tool_engine.py

@@ -245,6 +245,9 @@ def _convert_tool_response_to_str(tool_response: list[ToolInvokeMessage]) -> str
                     + "you do not need to create it, just tell the user to check it now."
                 )
             elif response.type == ToolInvokeMessage.MessageType.JSON:
+                json_message = cast(ToolInvokeMessage.JsonMessage, response.message)
+                if json_message.suppress_output:
+                    continue
                 json_parts.append(
                     json.dumps(
                         safe_json_value(cast(ToolInvokeMessage.JsonMessage, response.message).json_object),

api/core/tools/workflow_as_tool/tool.py

@@ -117,7 +117,7 @@ def _invoke(
         self._latest_usage = self._derive_usage_from_result(data)
 
         yield self.create_text_message(json.dumps(outputs, ensure_ascii=False))
-        yield self.create_json_message(outputs)
+        yield self.create_json_message(outputs, suppress_output=True)
 
     @property
     def latest_usage(self) -> LLMUsage: