add explanation

lang_agent/eval/validator.py

@@ -40,19 +40,21 @@ class Validator:
             api_key=self.config.api_key
         )
 
-    def default_correct(self, inputs: dict, outputs: dict, reference_outputs: dict) -> bool:
+    def default_correct(self, inputs: dict, outputs: dict, reference_outputs: dict) -> dict:
         instructions = (
             "Given an actual answer and an expected answer, determine whether"
             " the actual answer contains all of the information in the"
-            " expected answer. Respond with 'CORRECT' if the actual answer"
+            " expected answer. First provide your reasoning, then respond with"
-            " does contain all of the expected information and 'INCORRECT'"
+            " your final judgment.\n\n"
-            " otherwise. Do not include anything else in your response."
+            "Format your response EXACTLY as follows:\n"
+            "EXPLANATION: <your reasoning here>\n"
+            "JUDGMENT: <CORRECT or INCORRECT>"
         )
         actual_answer = outputs["output"][-1].content
         expected_answer = reference_outputs["answer"]
 
         if expected_answer is None:
-            return True
+            return {"score": True, "comment": "No expected answer provided, auto-pass."}
 
         user_msg = (
             f"ACTUAL ANSWER: {actual_answer}"
@@ -66,7 +68,24 @@ class Validator:
             ]
         )
 
-        return response.content.upper() == "CORRECT"
+        response_text = response.content
+        
+        # Parse the explanation and judgment from the response
+        explanation = ""
+        is_correct = False
+        
+        if "EXPLANATION:" in response_text:
+            parts = response_text.split("JUDGMENT:")
+            explanation = parts[0].replace("EXPLANATION:", "").strip()
+            if len(parts) > 1:
+                judgment = parts[1].strip().upper()
+                is_correct = "CORRECT" in judgment and "INCORRECT" not in judgment
+        else:
+            # Fallback: check if response contains CORRECT/INCORRECT
+            explanation = response_text
+            is_correct = "CORRECT" in response_text.upper() and "INCORRECT" not in response_text.upper()
+
+        return {"score": is_correct, "comment": explanation}
     
     def val_tool_use(self, inputs:dict, outputs:dict, reference_outputs:dict)->float:
         tool_uses:List[str] = reference_outputs.get("tool_use")