diff --git a/src/google/adk/tools/function_tool.py b/src/google/adk/tools/function_tool.py
index 3a168fb..a3bebd9 100644
--- a/src/google/adk/tools/function_tool.py
+++ b/src/google/adk/tools/function_tool.py
@@ -46,14 +46,14 @@ class FunctionTool(BaseTool):
 
     # Get documentation (prioritize direct __doc__ if available)
     if hasattr(func, '__doc__') and func.__doc__:
-      doc = func.__doc__
+      doc = inspect.cleandoc(func.__doc__)
     elif (
         hasattr(func, '__call__')
         and hasattr(func.__call__, '__doc__')
         and func.__call__.__doc__
     ):
       # For callable objects, try to get docstring from __call__ method
-      doc = func.__call__.__doc__
+      doc = inspect.cleandoc(func.__call__.__doc__)
 
     super().__init__(name=name, description=doc)
     self.func = func