diff --git a/ollama/_utils.py b/ollama/_utils.py
index 390dbe6..7059442 100644
--- a/ollama/_utils.py
+++ b/ollama/_utils.py
@@ -100,4 +100,4 @@ def convert_function_to_tool(func: Callable) -> Tool:
     )
   )
 
-  return tool
+  return Tool.model_validate(tool)