diff --git a/changelog.d/19320.misc b/changelog.d/19320.misc
new file mode 100644
index 00000000000..e18ad78c912
--- /dev/null
+++ b/changelog.d/19320.misc
@@ -0,0 +1 @@
+Tweak docstrings and signatures of `auth_types_for_event` and `get_catchup_room_event_ids`.
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index 66f50115e32..4b354dd6fbd 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -66,6 +66,7 @@
 from synapse.storage.databases.main.events_worker import EventRedactBehaviour
 from synapse.types import (
     MutableStateMap,
+    StateKey,
     StateMap,
     StrCollection,
     UserID,
@@ -1200,8 +1201,8 @@ def get_public_keys(invite_event: "EventBase") -> list[dict[str, Any]]:
 
 def auth_types_for_event(
     room_version: RoomVersion, event: Union["EventBase", "EventBuilder"]
-) -> set[tuple[str, str]]:
-    """Given an event, return a list of (EventType, StateKey) that may be
+) -> set[StateKey]:
+    """Given an event, return a list of (state event type, state key) that may be
     needed to auth the event. The returned list may be a superset of what
     would actually be required depending on the full state of the room.
 
diff --git a/synapse/storage/databases/main/transactions.py b/synapse/storage/databases/main/transactions.py
index 2fdd27d3da1..a3d75002b99 100644
--- a/synapse/storage/databases/main/transactions.py
+++ b/synapse/storage/databases/main/transactions.py
@@ -381,7 +381,7 @@ async def get_catch_up_room_event_ids(
     ) -> list[str]:
         """
         Returns at most 50 event IDs and their corresponding stream_orderings
-        that correspond to the oldest events that have not yet been sent to
+        that correspond to the newest events that have not yet been sent to
         the destination.
 
         Args: