fix: add a check in ComponentToolkit to avoid building a tool that builds tools (#4678)

* Enhance tool filtering logic by adding TOOL_TYPES set for output type checking

* Rename TOOL_TYPES to TOOL_TYPES_SET for clarity

src/backend/base/langflow/base/tools/component_tool.py

@@ -27,6 +27,9 @@ if TYPE_CHECKING:
     from langflow.schema.content_block import ContentBlock
 
 
+TOOL_TYPES_SET = {"Tool", "BaseTool", "StructuredTool"}
+
+
 def _get_input_type(_input: InputTypes):
     if _input.input_types:
         if len(_input.input_types) == 1:
@@ -165,7 +168,7 @@ class ComponentToolkit:
     ) -> list[BaseTool]:
         tools = []
         for output in self.component.outputs:
-            if output.name == TOOL_OUTPUT_NAME:
+            if output.name == TOOL_OUTPUT_NAME or any(tool_type in output.types for tool_type in TOOL_TYPES_SET):
                 continue
 
             if not output.method:

src/backend/base/langflow/components/tools/calculator.py

@@ -23,7 +23,6 @@ class CalculatorToolComponent(LCToolComponent):
             name="expression",
             display_name="Expression",
             info="The arithmetic expression to evaluate (e.g., '4*4*(33/22)+12-20').",
-            tool_mode=True,
         ),
     ]