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
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.elasticsearch.client.Request;
import org.elasticsearch.client.Response;
import org.elasticsearch.client.ResponseException;
import org.elasticsearch.geometry.Geometry;
import org.elasticsearch.geometry.LinearRing;
import org.elasticsearch.geometry.MultiPolygon;
import org.elasticsearch.geometry.Polygon;
import org.elasticsearch.geometry.Rectangle;
import org.elasticsearch.geometry.utils.WellKnownText;
import org.elasticsearch.search.aggregations.bucket.geogrid.GeoTileUtils;
import org.elasticsearch.test.rest.ESRestTestCase;
import org.hamcrest.Matchers;
import org.junit.AfterClass;
import org.junit.Before;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
/**
 * Rest test for _mvt end point. The test only check that the structure of the vector tiles is sound in
 * respect to the number of layers returned and the number of features abd tags in each layer.
 */
public class VectorTileRestIT extends ESRestTestCase {
    private static final String INDEX_POINTS = "index-points";
    private static final String INDEX_POLYGON = "index-polygon";
    private static final String INDEX_COLLECTION = "index-collection";
    private static final String INDEX_POINTS_SHAPES = INDEX_POINTS + "," + INDEX_POLYGON;