diff --git a/rdagent/core/proposal.py b/rdagent/core/proposal.py
index cf7e7cbf..58192be9 100644
--- a/rdagent/core/proposal.py
+++ b/rdagent/core/proposal.py
@@ -56,6 +56,7 @@ class Trace(Generic[ASpecificScen]):
 
     def get_last_experiment_info(self) -> Tuple[Hypothesis, ASpecificTask, Any]:
         """Access the last experiment result, sub-task, and the corresponding hypothesis."""
+        # TODO: The return value does not align with the signature.
         if not self.hist:
             return None
         last_hypothesis, last_experiment, _ = self.hist[-1]