diff --git a/synapse/storage/search.py b/synapse/storage/search.py
index 7d642e18ff..6c10f9631e 100644
--- a/synapse/storage/search.py
+++ b/synapse/storage/search.py
@@ -22,6 +22,17 @@ from synapse.storage.engines import PostgresEngine
 class SearchStore(SQLBaseStore):
     @defer.inlineCallbacks
     def search_msgs(self, room_ids, search_term, keys):
+        """Performs a full text search over events with give keys.
+
+        Args:
+            room_ids (list): List of room ids to search in
+            search_term (str): Search term to search for
+            keys (list): List of keys to search in, currently supports
+                "content.body", "content.name", "content.body"
+
+        Returns:
+            2-tuple of (dict event_id -> rank, dict event_id -> event)
+        """
         clauses = []
         args = []