diff --git a/rdagent/components/coder/CoSTEER/evaluators.py b/rdagent/components/coder/CoSTEER/evaluators.py
index 612b6895..4c4f4dae 100644
--- a/rdagent/components/coder/CoSTEER/evaluators.py
+++ b/rdagent/components/coder/CoSTEER/evaluators.py
@@ -43,6 +43,34 @@ class CoSTEERSingleFeedback(Feedback):
     code: str
     final_decision: bool
 
+    @staticmethod
+    def val_and_update_init_dict(data: dict) -> dict:
+        # TODO: (bowen) use a more general method to validate and update the data dictionary before init, like pydantic
+        """
+        Validates and converts the 'final_decision' field in the given data dictionary.
+
+        Args:
+            data (dict): The data dictionary containing the 'final_decision' field.
+
+        Returns:
+            dict: The updated data dictionary with 'final_decision' as a boolean.
+
+        Raises:
+            ValueError: If 'final_decision' is not present or not a boolean.
+        """
+        if "final_decision" not in data:
+            raise ValueError("'final_decision' is required")
+
+        if isinstance(data["final_decision"], str):
+            if data["final_decision"] == "false" or data["final_decision"] == "False":
+                data["final_decision"] = False
+            elif data["final_decision"] == "true" or data["final_decision"] == "True":
+                data["final_decision"] = True
+
+        if not isinstance(data["final_decision"], bool):
+            raise ValueError(f"'final_decision' must be a boolean, not {type(data['final_decision'])}")
+        return data
+
     def __str__(self) -> str:
         return f"""------------------Execution------------------
 {self.execution}
diff --git a/rdagent/components/coder/data_science/ensemble/eval.py b/rdagent/components/coder/data_science/ensemble/eval.py
index e6a4b72f..d84e0758 100644
--- a/rdagent/components/coder/data_science/ensemble/eval.py
+++ b/rdagent/components/coder/data_science/ensemble/eval.py
@@ -81,6 +81,11 @@ class EnsembleCoSTEEREvaluator(CoSTEEREvaluator):
             stdout=stdout,
             workflow_stdout=workflow_stdout,
         )
-        efb = build_cls_from_json_with_retry(EnsembleEvalFeedback, system_prompt=system_prompt, user_prompt=user_prompt)
+        efb = build_cls_from_json_with_retry(
+            EnsembleEvalFeedback,
+            system_prompt=system_prompt,
+            user_prompt=user_prompt,
+            init_kwargs_update_func=EnsembleEvalFeedback.val_and_update_init_dict,
+        )
         efb.final_decision = efb.final_decision and ret_code == 0
         return efb
diff --git a/rdagent/components/coder/data_science/feature/eval.py b/rdagent/components/coder/data_science/feature/eval.py
index f09f8eda..148a511c 100644
--- a/rdagent/components/coder/data_science/feature/eval.py
+++ b/rdagent/components/coder/data_science/feature/eval.py
@@ -72,4 +72,9 @@ class FeatureCoSTEEREvaluator(CoSTEEREvaluator):
             workflow_stdout=workflow_stdout,
         )
 
-        return build_cls_from_json_with_retry(FeatureEvalFeedback, system_prompt=system_prompt, user_prompt=user_prompt)
+        return build_cls_from_json_with_retry(
+            FeatureEvalFeedback,
+            system_prompt=system_prompt,
+            user_prompt=user_prompt,
+            init_kwargs_update_func=FeatureEvalFeedback.val_and_update_init_dict,
+        )
diff --git a/rdagent/components/coder/data_science/model/eval.py b/rdagent/components/coder/data_science/model/eval.py
index a1b03fb2..4b145896 100644
--- a/rdagent/components/coder/data_science/model/eval.py
+++ b/rdagent/components/coder/data_science/model/eval.py
@@ -90,4 +90,9 @@ class ModelGeneralCaseSpecEvaluator(CoSTEEREvaluator):
             stdout=stdout,
             workflow_stdout=workflow_stdout,
         )
-        return build_cls_from_json_with_retry(ModelSingleFeedback, system_prompt=system_prompt, user_prompt=user_prompt)
+        return build_cls_from_json_with_retry(
+            ModelSingleFeedback,
+            system_prompt=system_prompt,
+            user_prompt=user_prompt,
+            init_kwargs_update_func=ModelSingleFeedback.val_and_update_init_dict,
+        )
diff --git a/rdagent/components/coder/data_science/raw_data_loader/eval.py b/rdagent/components/coder/data_science/raw_data_loader/eval.py
index 58d84327..8a6f6972 100644
--- a/rdagent/components/coder/data_science/raw_data_loader/eval.py
+++ b/rdagent/components/coder/data_science/raw_data_loader/eval.py
@@ -81,5 +81,8 @@ class DataLoaderCoSTEEREvaluator(CoSTEEREvaluator):
         )
 
         return build_cls_from_json_with_retry(
-            DataLoaderEvalFeedback, system_prompt=system_prompt, user_prompt=user_prompt
+            DataLoaderEvalFeedback,
+            system_prompt=system_prompt,
+            user_prompt=user_prompt,
+            init_kwargs_update_func=DataLoaderEvalFeedback.val_and_update_init_dict,
         )
diff --git a/rdagent/components/coder/data_science/workflow/eval.py b/rdagent/components/coder/data_science/workflow/eval.py
index 9df1a07c..5d25777c 100644
--- a/rdagent/components/coder/data_science/workflow/eval.py
+++ b/rdagent/components/coder/data_science/workflow/eval.py
@@ -121,7 +121,10 @@ class WorkflowGeneralCaseSpecEvaluator(CoSTEEREvaluator):
             code=implementation.file_dict["main.py"],
         )
         wfb = build_cls_from_json_with_retry(
-            WorkflowSingleFeedback, system_prompt=system_prompt, user_prompt=user_prompt
+            WorkflowSingleFeedback,
+            system_prompt=system_prompt,
+            user_prompt=user_prompt,
+            init_kwargs_update_func=WorkflowSingleFeedback.val_and_update_init_dict,
         )
         if score_ret_code != 0:
             wfb.final_decision = False
diff --git a/rdagent/scenarios/data_science/dev/runner/eval.py b/rdagent/scenarios/data_science/dev/runner/eval.py
index 1b2e6cc0..35e2507f 100644
--- a/rdagent/scenarios/data_science/dev/runner/eval.py
+++ b/rdagent/scenarios/data_science/dev/runner/eval.py
@@ -85,7 +85,10 @@ class DSCoSTEERCoSTEEREvaluator(CoSTEEREvaluator):
         )
 
         feedback = build_cls_from_json_with_retry(
-            DSCoSTEEREvalFeedback, system_prompt=system_prompt, user_prompt=user_prompt
+            DSCoSTEEREvalFeedback,
+            system_prompt=system_prompt,
+            user_prompt=user_prompt,
+            init_kwargs_update_func=DSCoSTEEREvalFeedback.val_and_update_init_dict,
         )
 
         if feedback: