Update tools.py

tools.py

@@ -2,6 +2,7 @@ from langchain_community.retrievers import BM25Retriever
 from langchain.tools import Tool
 from langchain_community.tools import DuckDuckGoSearchRun
 from langchain_community.document_loaders.wikipedia import WikipediaLoader
+from langchain_community.document_loaders import YoutubeLoader
 from langchain_core.tools import tool