diff --git a/protos/route_guide.proto b/protos/route_guide.proto
index 7cda80e..3759049 100644
--- a/protos/route_guide.proto
+++ b/protos/route_guide.proto
@@ -38,6 +38,9 @@ service RouteGuide {
   // A simple RPC.
   //
   // Obtains the feature at a given position.
+  //
+  // A feature with an empty name is returned if there's no feature at the given
+  // position.
   rpc GetFeature(Point) returns (Feature) {}
 
   // A server-to-client streaming RPC.