diff --git a/hgext/narrow/narrowrepo.py b/hgext/narrow/narrowrepo.py
--- a/hgext/narrow/narrowrepo.py
+++ b/hgext/narrow/narrowrepo.py
@@ -75,6 +75,10 @@
 
         @localrepo.repofilecache(narrowspec.FILENAME)
         def narrowpats(self):
+            """matcher patterns for this repository's narrowspec
+
+            A tuple of (includes, excludes).
+            """
             return narrowspec.load(self)
 
         @localrepo.repofilecache(narrowspec.FILENAME)