chore(llmobs): description should be optional when create_dataset (#14275)

description should be optional when create_dataset

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Author: gary-huang

ddtrace/llmobs/_llmobs.py

@@ -631,7 +631,7 @@ def pull_dataset(cls, name: str) -> Dataset:
         return ds
 
     @classmethod
-    def create_dataset(cls, name: str, description: str, records: Optional[List[DatasetRecord]] = None) -> Dataset:
+    def create_dataset(cls, name: str, description: str = "", records: Optional[List[DatasetRecord]] = None) -> Dataset:
         if records is None:
             records = []
         ds = cls._instance._dne_client.dataset_create(name, description)

ddtrace/llmobs/_writer.py

@@ -357,14 +357,13 @@ def dataset_create(self, name: str, description: str) -> Dataset:
 
     @staticmethod
     def _get_record_json(record: Union[UpdatableDatasetRecord, DatasetRecordRaw], is_update: bool) -> JSONType:
-        # for now, if a user wants to "erase" the value of expected_output, they are expected to
-        # set expected_output to None, and we serialize that as empty string to indicate this to BE
+        # for now, if a user wants to "erase" the value of expected_output or metadata, they are expected to
+        # set it to None, and we serialize an empty string (for expected_output) and empty dict (for metadata)
+        # to indicate this erasure to BE
         expected_output: JSONType = None
         if "expected_output" in record:
             expected_output = "" if record["expected_output"] is None else record["expected_output"]
 
-        # for now, if a user wants to "erase" the value of metadata, they are expected to
-        # set metadata to None, and we serialize that as an empty map to indicate this to BE
         metadata: JSONType = None
         if "metadata" in record:
             metadata = {} if record["metadata"] is None else record["metadata"]