updated user docstrings

Author: cemde

maseval/core/user.py

@@ -74,15 +74,15 @@ def is_done(self) -> bool:
         """
         ...
 
-    def get_tool(self):
+    def get_tool(self) -> Any:
         """Return a framework-compatible tool for agent interaction.
 
         Some frameworks (smolagents, CAMEL) use a tool-based pattern where
         agents invoke an AskUser tool to interact with the user. Override
         this in subclasses for frameworks that need it.
 
         Returns:
-            Framework-specific tool, or None if not applicable.
+            Framework-specific tool, or `None` if not applicable.
         """
         return None