diff --git a/src/courier/types/journey_node.py b/src/courier/types/journey_node.py
index 69043ba..d834ead 100644
--- a/src/courier/types/journey_node.py
+++ b/src/courier/types/journey_node.py
@@ -100,7 +100,11 @@ class JourneyBatchNode(BaseModel):
 class JourneyAddToDigestNode(BaseModel):
     """Add the current event to a digest keyed by the given subscription topic.
 
-    The digest accumulates events and releases them on the schedule configured for the topic.
+    The digest accumulates events and releases them on the schedule configured for the topic, using the notification template configured on that topic.
+
+    **The topic must have a template configured.** If the topic has no template when the first event reaches this node, the journey run fails immediately: the run is marked `ERROR`, no digest instance is created, and the journey does not continue past this node. Configure the topic's template before using the topic in a journey.
+
+    If the journey run is scoped to a tenant, digests are kept separate per tenant: two runs for the same user under different tenants accumulate and release as separate digests, even on the same topic.
     """
 
     subscription_topic_id: str
diff --git a/src/courier/types/journey_node_param.py b/src/courier/types/journey_node_param.py
index 5d4e069..526db0c 100644
--- a/src/courier/types/journey_node_param.py
+++ b/src/courier/types/journey_node_param.py
@@ -99,7 +99,11 @@ class JourneyBatchNode(TypedDict, total=False):
 class JourneyAddToDigestNode(TypedDict, total=False):
     """Add the current event to a digest keyed by the given subscription topic.
 
-    The digest accumulates events and releases them on the schedule configured for the topic.
+    The digest accumulates events and releases them on the schedule configured for the topic, using the notification template configured on that topic.
+
+    **The topic must have a template configured.** If the topic has no template when the first event reaches this node, the journey run fails immediately: the run is marked `ERROR`, no digest instance is created, and the journey does not continue past this node. Configure the topic's template before using the topic in a journey.
+
+    If the journey run is scoped to a tenant, digests are kept separate per tenant: two runs for the same user under different tenants accumulate and release as separate digests, even on the same topic.
     """
 
     subscription_topic_id: Required[str]