Currently if you add a field in the fields parameter with a wildcard, no fields will be added to the hits layer. The situation is even worst if the wildcard matches the field name of the geo_point or geo_shape field, in that case a ClassCastException is thrown.
x-pack/plugin/vector-tile/src/javaRestTest/java/org/elasticsearch/xpack/vectortile/VectorTileRestIT.java
final VectorTile.Tile tile = execute(mvtRequest);
            assertThat(tile.getLayersCount(), Matchers.equalTo(3));
            assertLayer(tile, HITS_LAYER, 4096, 33, 2);
            assertLayer(tile, AGGS_LAYER, 4096, 1, 2);
            assertLayer(tile, META_LAYER, 4096, 1, 13);
            assertStringTag(getLayer(tile, META_LAYER), getLayer(tile, META_LAYER).getFeatures(0), "hits.total.relation", "eq");
            assertSintTag(getLayer(tile, META_LAYER), getLayer(tile, META_LAYER).getFeatures(0), "hits.total.value", 33);
        }
        {
            final Request mvtRequest = new Request(getHttpMethod(), INDEX_POINTS + "/_mvt/location/" + z + "/" + x + "/" + y);
            mvtRequest.setJsonEntity("{\"track_total_hits\": false }");
            final VectorTile.Tile tile = execute(mvtRequest);
            assertThat(tile.getLayersCount(), Matchers.equalTo(3));
            assertLayer(tile, HITS_LAYER, 4096, 33, 2);
            assertLayer(tile, AGGS_LAYER, 4096, 1, 2);
            assertLayer(tile, META_LAYER, 4096, 1, 11);
        }
    }
    public void testTrackTotalHitsAsInt() throws Exception {
        {
            final Request mvtRequest = new Request(
                getHttpMethod(),
                INDEX_POINTS + "/_mvt/location/" + z + "/" + x + "/" + y + "?track_total_hits=100"
            );
            final VectorTile.Tile tile = execute(mvtRequest);
            assertThat(tile.getLayersCount(), Matchers.equalTo(3));
            assertLayer(tile, HITS_LAYER, 4096, 33, 2);
            assertLayer(tile, AGGS_LAYER, 4096, 1, 2);
            assertLayer(tile, META_LAYER, 4096, 1, 13);
            assertStringTag(getLayer(tile, META_LAYER), getLayer(tile, META_LAYER).getFeatures(0), "hits.total.relation", "eq");