diff --git a/src/ol/View.js b/src/ol/View.js
index ab9155b9b8..591b13e133 100644
--- a/src/ol/View.js
+++ b/src/ol/View.js
@@ -1465,9 +1465,10 @@ class View extends BaseObject {
   /**
    * Get a valid zoom level according to the current view constraints.
    * @param {number|undefined} targetZoom Target zoom.
-   * @param {number=} opt_direction Direction. Default is `0`. Specify `-1` or `1` to return
-   * the available value respectively lower or greater than the target one. Leaving `0` will simply choose
-   * the nearest available value.
+   * @param {number=} [opt_direction=0] Indicate which resolution should be used
+   * by a renderer if the view resolution does not match any resolution of the tile source.
+   * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
+   * will be used. If -1, the nearest higher resolution will be used.
    * @return {number|undefined} Valid zoom level.
    */
   getConstrainedZoom(targetZoom, opt_direction) {
@@ -1478,9 +1479,10 @@ class View extends BaseObject {
   /**
    * Get a valid resolution according to the current view constraints.
    * @param {number|undefined} targetResolution Target resolution.
-   * @param {number=} opt_direction Direction. Default is `0`. Specify `-1` or `1` to return
-   * the available value respectively lower or greater than the target one. Leaving `0` will simply choose
-   * the nearest available value.
+   * @param {number=} [opt_direction=0] Indicate which resolution should be used
+   * by a renderer if the view resolution does not match any resolution of the tile source.
+   * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
+   * will be used. If -1, the nearest higher resolution will be used.
    * @return {number|undefined} Valid resolution.
    */
   getConstrainedResolution(targetResolution, opt_direction) {