diff --git a/tom_observations/facility.py b/tom_observations/facility.py
index 8a3c302a4..93d2d044e 100644
--- a/tom_observations/facility.py
+++ b/tom_observations/facility.py
@@ -241,6 +241,8 @@ def validate_observation(self, observation_payload):
         """
         Same thing as submit_observation, but a dry run. You can
         skip this in different modules by just using "pass"
+
+        Typically called by the ObservationForm.is_valid() method.
         """
         pass