Improved message when CL description is missing

presubmit_canned_checks.py

Index: presubmit_canned_checks.py
diff --git a/presubmit_canned_checks.py b/presubmit_canned_checks.py
index 56031b2c9828dfdfa9b82329751320e4f884b4c5..8be4f52971c6849d2b7122a4d94fb140a0354dd0 100644
--- a/presubmit_canned_checks.py
+++ b/presubmit_canned_checks.py
@@ -61,9 +61,9 @@ def CheckChangeHasDescription(input_api, output_api):
   text = input_api.change.DescriptionText()
   if text.strip() == '':
     if input_api.is_committing:
-      return [output_api.PresubmitError('Add a description.')]
+      return [output_api.PresubmitError('Add a description to the CL.')]
     else:
-      return [output_api.PresubmitNotifyResult('Add a description.')]
+      return [output_api.PresubmitNotifyResult('Add a description to the CL.')]
   return []