diff --git a/packages/engine/Source/Core/GeometryFactory.js b/packages/engine/Source/Core/GeometryFactory.js
index 10ee22d3cf1..519c21573f5 100644
--- a/packages/engine/Source/Core/GeometryFactory.js
+++ b/packages/engine/Source/Core/GeometryFactory.js
@@ -1,21 +1,70 @@
 import DeveloperError from "../Core/DeveloperError.js";
 
 /**
- * Base class for all geometry creation utility classes that can be passed to {@link GeometryInstance}
- * for asynchronous geometry creation.
+ * Describes a geometry type that can be converted into a {@link Geometry}.
+ * <p>
+ * Implementations of this interface are the core geometry "description" classes
+ * such as {@link BoxGeometry}, {@link RectangleGeometry},
+ * {@link EllipsoidGeometry}, and other classes with a static
+ * <code>createGeometry</code> function. Instances of these classes can be
+ * passed to {@link GeometryInstance} and {@link Primitive} to have their
+ * vertices and indices created either asynchronously on a web worker or
+ * synchronously on the main thread.
+ * </p>
+ * <p>
+ * This type describes an interface and is not intended to be instantiated
+ * directly.
+ * </p>
  *
+ * @alias GeometryFactory
  * @constructor
- * @class
  * @abstract
+ *
+ * @see BoxGeometry
+ * @see BoxOutlineGeometry
+ * @see CircleGeometry
+ * @see CircleOutlineGeometry
+ * @see CoplanarPolygonGeometry
+ * @see CoplanarPolygonOutlineGeometry
+ * @see CorridorGeometry
+ * @see CorridorOutlineGeometry
+ * @see CylinderGeometry
+ * @see CylinderOutlineGeometry
+ * @see EllipseGeometry
+ * @see EllipseOutlineGeometry
+ * @see EllipsoidGeometry
+ * @see EllipsoidOutlineGeometry
+ * @see FrustumGeometry
+ * @see FrustumOutlineGeometry
+ * @see GroundPolylineGeometry
+ * @see PlaneGeometry
+ * @see PlaneOutlineGeometry
+ * @see PolygonGeometry
+ * @see PolygonOutlineGeometry
+ * @see PolylineGeometry
+ * @see PolylineVolumeGeometry
+ * @see PolylineVolumeOutlineGeometry
+ * @see RectangleGeometry
+ * @see RectangleOutlineGeometry
+ * @see SimplePolylineGeometry
+ * @see SphereGeometry
+ * @see SphereOutlineGeometry
+ * @see WallGeometry
+ * @see WallOutlineGeometry
  */
 function GeometryFactory() {
   DeveloperError.throwInstantiationError();
 }
 
 /**
- * Returns a geometry.
+ * Creates a {@link Geometry} from a geometry description.
+ * <p>
+ * Concrete geometry classes (for example {@link RectangleGeometry}) implement
+ * this function as a static method that takes an instance of the corresponding
+ * geometry description and returns the computed vertices and indices.
+ * </p>
  *
- * @param {GeometryFactory} geometryFactory A description of the circle.
+ * @param {GeometryFactory} geometryFactory The geometry description to create.
  * @returns {Geometry|undefined} The computed vertices and indices.
  */
 GeometryFactory.createGeometry = function (geometryFactory) {
diff --git a/packages/engine/Source/Core/GeometryInstance.js b/packages/engine/Source/Core/GeometryInstance.js
index d5316efdc7c..45958565c1a 100644
--- a/packages/engine/Source/Core/GeometryInstance.js
+++ b/packages/engine/Source/Core/GeometryInstance.js
@@ -14,6 +14,12 @@ import Matrix4 from "./Matrix4.js";
  *
  * @param {object} options Object with the following properties:
  * @param {Geometry|GeometryFactory} options.geometry The geometry to instance.
+ *        When a {@link Geometry} is passed, it will be used directly. When an
+ *        object implementing {@link GeometryFactory} is passed (for example an
+ *        instance of {@link RectangleGeometry} or {@link EllipsoidGeometry}),
+ *        the actual geometry will be created either asynchronously on a web
+ *        worker or synchronously on the main thread depending on the
+ *        {@link Primitive} options.
  * @param {Matrix4} [options.modelMatrix=Matrix4.IDENTITY] The model matrix that transforms to transform the geometry from model to world coordinates.
  * @param {object} [options.id] A user-defined object to return when the instance is picked with {@link Scene#pick} or get/set per-instance attributes with {@link Primitive#getGeometryInstanceAttributes}.
  * @param {object} [options.attributes] Per-instance attributes like a show or color attribute shown in the example below.