diff --git a/src/ol/control/overviewmapcontrol.js b/src/ol/control/overviewmapcontrol.js
index 124d0a8224..15a0624579 100644
--- a/src/ol/control/overviewmapcontrol.js
+++ b/src/ol/control/overviewmapcontrol.js
@@ -515,7 +515,8 @@ ol.control.OverviewMap.prototype.setCollapsed = function(collapsed) {
 
 
 /**
- * @return {boolean} True if the widget is collapsed.
+ * Determine if the overview map is collapsed.
+ * @return {boolean} The overview map is collapsed.
  * @api stable
  */
 ol.control.OverviewMap.prototype.getCollapsed = function() {
diff --git a/src/ol/feature.js b/src/ol/feature.js
index 14a08756d2..126edf8805 100644
--- a/src/ol/feature.js
+++ b/src/ol/feature.js
@@ -149,6 +149,9 @@ ol.Feature.prototype.getGeometry = function() {
 
 
 /**
+ * Get the feature identifier.  This is a stable identifier for the feature and
+ * is either set when reading data from a remote source or set explicitly by
+ * calling {@link ol.Feature#setId}.
  * @return {number|string|undefined} Id.
  * @api stable
  * @observable
diff --git a/src/ol/imagetile.js b/src/ol/imagetile.js
index 52d7b4aee1..4750d17970 100644
--- a/src/ol/imagetile.js
+++ b/src/ol/imagetile.js
@@ -76,6 +76,7 @@ ol.ImageTile.prototype.disposeInternal = function() {
 
 
 /**
+ * Get the image element for this tile.
  * @inheritDoc
  * @api
  */
diff --git a/src/ol/interaction/draganddropinteraction.js b/src/ol/interaction/draganddropinteraction.js
index 4496ef4414..2297e2316d 100644
--- a/src/ol/interaction/draganddropinteraction.js
+++ b/src/ol/interaction/draganddropinteraction.js
@@ -219,18 +219,21 @@ ol.interaction.DragAndDropEvent =
   goog.base(this, type, target);
 
   /**
+   * The features parsed from dropped data.
    * @type {Array.<ol.Feature>|undefined}
    * @api stable
    */
   this.features = opt_features;
 
   /**
+   * The dropped file.
    * @type {File}
    * @api stable
    */
   this.file = file;
 
   /**
+   * The feature projection.
    * @type {ol.proj.Projection|undefined}
    * @api
    */
diff --git a/src/ol/observable.js b/src/ol/observable.js
index 3bc9020410..d5e409e550 100644
--- a/src/ol/observable.js
+++ b/src/ol/observable.js
@@ -62,6 +62,8 @@ ol.Observable.prototype.changed = function() {
 
 
 /**
+ * Get the version number for this object.  Each time the object is modified,
+ * its version number will be incremented.
  * @return {number} Revision.
  * @api
  */
diff --git a/src/ol/render/renderevent.js b/src/ol/render/renderevent.js
index 6d8810ae7e..9a0e647c2c 100644
--- a/src/ol/render/renderevent.js
+++ b/src/ol/render/renderevent.js
@@ -53,6 +53,7 @@ ol.render.Event = function(
   this.vectorContext = opt_vectorContext;
 
   /**
+   * An object representing the current render frame state.
    * @type {olx.FrameState|undefined}
    * @api
    */
diff --git a/src/ol/render/vectorcontext.js b/src/ol/render/vectorcontext.js
index 80edf8425d..5345a592a0 100644
--- a/src/ol/render/vectorcontext.js
+++ b/src/ol/render/vectorcontext.js
@@ -3,6 +3,8 @@ goog.provide('ol.render.VectorContext');
 
 
 /**
+ * Context for drawing geometries.  A vector context is available on render
+ * events and does not need to be constructed directly.
  * @constructor
  * @struct
  * @api
diff --git a/src/ol/render/webgl/webglimmediate.js b/src/ol/render/webgl/webglimmediate.js
index 2a54aedcff..8e7fb7ad81 100644
--- a/src/ol/render/webgl/webglimmediate.js
+++ b/src/ol/render/webgl/webglimmediate.js
@@ -93,6 +93,9 @@ ol.render.webgl.Immediate.prototype.flush = function() {
 
 
 /**
+ * Register a function to be called for rendering at a given zIndex.  The
+ * function will be called asynchronously.  The callback will receive a
+ * reference to {@link ol.render.canvas.Immediate} context for drawing.
  * @param {number} zIndex Z index.
  * @param {function(ol.render.webgl.Immediate)} callback Callback.
  * @api
diff --git a/src/ol/source/wmtssource.js b/src/ol/source/wmtssource.js
index d4943717ad..08ddff7e4c 100644
--- a/src/ol/source/wmtssource.js
+++ b/src/ol/source/wmtssource.js
@@ -313,6 +313,7 @@ ol.source.WMTS.prototype.updateDimensions = function(dimensions) {
 
 
 /**
+ * Generate source options from a capabilities object.
  * @param {Object} wmtsCap An object representing the capabilities document.
  * @param {Object} config Configuration properties for the layer.  Defaults for
  *                  the layer will apply if not provided.
diff --git a/src/ol/style/imagestyle.js b/src/ol/style/imagestyle.js
index aa71da5586..415aaeb868 100644
--- a/src/ol/style/imagestyle.js
+++ b/src/ol/style/imagestyle.js
@@ -119,6 +119,8 @@ ol.style.Image.prototype.getSnapToPixel = function() {
 
 
 /**
+ * Get the anchor point.  The anchor determines the center point for the
+ * symbolizer.  Its units are determined by `anchorXUnits` and `anchorYUnits`.
  * @function
  * @return {Array.<number>} Anchor.
  */
@@ -126,6 +128,7 @@ ol.style.Image.prototype.getAnchor = goog.abstractMethod;
 
 
 /**
+ * Get the image element for the symbolizer.
  * @function
  * @param {number} pixelRatio Pixel ratio.
  * @return {HTMLCanvasElement|HTMLVideoElement|Image} Image element.
@@ -159,6 +162,7 @@ ol.style.Image.prototype.getHitDetectionImageSize = goog.abstractMethod;
 
 
 /**
+ * Get the origin of the symbolizer.
  * @function
  * @return {Array.<number>} Origin.
  */
@@ -166,6 +170,7 @@ ol.style.Image.prototype.getOrigin = goog.abstractMethod;
 
 
 /**
+ * Get the size of the symbolizer (in pixels).
  * @function
  * @return {ol.Size} Size.
  */