diff --git a/lib/cartodb/backends/layer-stats/mapnik-layer-stats.js b/lib/cartodb/backends/layer-stats/mapnik-layer-stats.js
index b5818bc7..49988aa8 100644
--- a/lib/cartodb/backends/layer-stats/mapnik-layer-stats.js
+++ b/lib/cartodb/backends/layer-stats/mapnik-layer-stats.js
@@ -122,6 +122,9 @@ function firstPhaseQueries(queries, ctx) {
 
     // aggrFeatureCount
     if (ctx.metaOptions.hasOwnProperty('aggrFeatureCount')) {
+        // We expect as zoom level as the value of aggrFeatureCount
+        // TODO: it'd be nice to admit an array of zoom levels to
+        // return metadata for multiple levels.
         addStat(
             queries,
             ctx,