diff --git a/src/ol/source/formatvectorsource.js b/src/ol/source/formatvectorsource.js
index 209b90c5dd..b3b831f6c6 100644
--- a/src/ol/source/formatvectorsource.js
+++ b/src/ol/source/formatvectorsource.js
@@ -20,6 +20,11 @@ goog.require('ol.xml');
 
 
 /**
+ * @classdesc
+ * Abstract base class; normally only used for creating subclasses and not
+ * instantiated in apps.
+ * Base class for vector sources in one of the supported formats.
+ *
  * @constructor
  * @extends {ol.source.Vector}
  * @param {olx.source.FormatVectorOptions} options Options.
diff --git a/src/ol/source/servervectorsource.js b/src/ol/source/servervectorsource.js
index 3b6a361c92..bb5c72bff2 100644
--- a/src/ol/source/servervectorsource.js
+++ b/src/ol/source/servervectorsource.js
@@ -10,6 +10,10 @@ goog.require('ol.structs.RBush');
 
 
 /**
+ * @classdesc
+ * A vector source in one of the supported formats, using a custom function to
+ * read in the data from a remote server.
+ *
  * @constructor
  * @extends {ol.source.FormatVector}
  * @param {olx.source.ServerVectorOptions} options Options.
diff --git a/src/ol/source/staticvectorsource.js b/src/ol/source/staticvectorsource.js
index 3baf406036..f412b32886 100644
--- a/src/ol/source/staticvectorsource.js
+++ b/src/ol/source/staticvectorsource.js
@@ -6,6 +6,12 @@ goog.require('ol.source.State');
 
 
 /**
+ * @classdesc
+ * Abstract base class; normally only used for creating subclasses and not
+ * instantiated in apps.
+ * Base class for vector sources in one of the supported formats, where the data
+ * is read from a file or other static source.
+ *
  * @constructor
  * @extends {ol.source.FormatVector}
  * @fires ol.source.VectorEvent
diff --git a/src/ol/source/tilevectorsource.js b/src/ol/source/tilevectorsource.js
index 5e9d5c33c2..0e8ff03531 100644
--- a/src/ol/source/tilevectorsource.js
+++ b/src/ol/source/tilevectorsource.js
@@ -11,6 +11,10 @@ goog.require('ol.tilegrid.TileGrid');
 
 
 /**
+ * @classdesc
+ * A vector source in one of the supported formats, where the data is divided
+ * into tiles in a fixed grid pattern.
+ *
  * @constructor
  * @extends {ol.source.FormatVector}
  * @param {olx.source.TileVectorOptions} options Options.