diff --git a/health_rec/services/retriever.py b/health_rec/services/retriever.py
index 771caac..9262814 100644
--- a/health_rec/services/retriever.py
+++ b/health_rec/services/retriever.py
@@ -1,5 +1,6 @@
+"""Service for retrieving documents using ChromaDB vector similarity search."""
+
 import logging
-from dataclasses import dataclass
 from typing import List
 
 import chromadb
@@ -26,8 +27,7 @@ def __init__(self) -> None:
         self.client = openai.Client(api_key=Config.OPENAI_API_KEY)
         self.embedding_model = Config.OPENAI_EMBEDDING
         self.chroma_client = chromadb.HttpClient(
-            host=Config.CHROMA_HOST,
-            port=Config.CHROMA_PORT
+            host=Config.CHROMA_HOST, port=Config.CHROMA_PORT
         )
         self.collection: Collection = self.chroma_client.get_collection(
             name=Config.COLLECTION_NAME
@@ -54,10 +54,7 @@ def _generate_embedding(self, text: str) -> List[float]:
         """
         try:
             return (
-                self.client.embeddings.create(
-                    input=[text],
-                    model=self.embedding_model
-                )
+                self.client.embeddings.create(input=[text], model=self.embedding_model)
                 .data[0]
                 .embedding
             )
@@ -73,6 +70,8 @@ def retrieve(self, query: str, n_results: int = 5) -> List[ServiceDocument]:
         ----------
         query : str
             The search query.
+        n_results : int, optional
+            The number of results to retrieve, by default 5.
 
         Returns
         -------
@@ -90,13 +89,12 @@ def retrieve(self, query: str, n_results: int = 5) -> List[ServiceDocument]:
 
             # Retrieve documents from ChromaDB
             results: QueryResult = self.collection.query(
-                query_embeddings=query_embedding,
-                n_results=n_results
+                query_embeddings=query_embedding, n_results=n_results
             )
 
             # Parse and return results
-            return _parse_chroma_result(results)
+            return _parse_chroma_result(results)  # type: ignore
 
         except Exception as e:
             logger.error(f"Error in Retriever.retrieve: {e}")
-            raise
\ No newline at end of file
+            raise