chore(core): fix some docstrings (from DOC preview rule) (#32833)

* Add `Raises` sections
* Add `Returns` sections
* Add `Yields` sections

---------

Co-authored-by: Mason Daugherty <mason@langchain.dev>

libs/core/langchain_core/exceptions.py

@@ -42,6 +42,10 @@ class OutputParserException(ValueError, LangChainException):  # noqa: N818
                 previous output was improperly structured, in the hopes that it will
                 update the output to the correct format.
                 Defaults to False.
+
+        Raises:
+            ValueError: If ``send_to_llm`` is True but either observation or
+                ``llm_output`` are not provided.
         """
         if isinstance(error, str):
             error = create_message(
@@ -77,6 +81,9 @@ def create_message(*, message: str, error_code: ErrorCode) -> str:
     Args:
         message: The message to display.
         error_code: The error code to display.
+
+    Returns:
+        The full message with the troubleshooting link.
     """
     return (
         f"{message}\n"