diff --git a/.jsduck/categories.json b/.jsduck/categories.json
index 351d2fc5c4..55d7a82dc5 100644
--- a/.jsduck/categories.json
+++ b/.jsduck/categories.json
@@ -19,6 +19,7 @@
 			{
 				"name": "User Interface",
 				"classes": [
+					"ve.ui.MWAriaDescribe",
 					"ve.ui.MW*Page",
 					"ve.ui.MW*Window"
 				]
diff --git a/.jsduck/mw-categories.json b/.jsduck/mw-categories.json
index 881ce354a1..bd7e76ab7d 100644
--- a/.jsduck/mw-categories.json
+++ b/.jsduck/mw-categories.json
@@ -19,6 +19,7 @@
 			{
 				"name": "User Interface",
 				"classes": [
+					"ve.ui.MWAriaDescribe",
 					"ve.ui.MW*Page",
 					"ve.ui.MW*Window"
 				]
diff --git a/extension.json b/extension.json
index 2a6b2a81f6..c555dc77af 100644
--- a/extension.json
+++ b/extension.json
@@ -2148,6 +2148,7 @@
 				"modules/ve-mw/dm/models/ve.dm.MWTemplateModel.js",
 				"modules/ve-mw/dm/models/ve.dm.MWTemplatePlaceholderModel.js",
 				"modules/ve-mw/dm/models/ve.dm.MWParameterModel.js",
+				"modules/ve-mw/ui/ve.ui.MWAriaDescribe.js",
 				"modules/ve-mw/ui/widgets/ve.ui.MWDismissibleMessageWidget.js",
 				"modules/ve-mw/ui/widgets/ve.ui.MWParameterCheckboxInputWidget.js",
 				"modules/ve-mw/ui/widgets/ve.ui.MWParameterSearchWidget.js",
@@ -2246,6 +2247,7 @@
 				"visualeditor-dialog-transclusion-param-example-long",
 				"visualeditor-dialog-transclusion-param-info",
 				"visualeditor-dialog-transclusion-param-info-missing",
+				"visualeditor-dialog-transclusion-param-selection-aria-description",
 				"visualeditor-dialog-transclusion-param-selection-aria-label",
 				"visualeditor-dialog-transclusion-param-undocumented",
 				"visualeditor-dialog-transclusion-placeholder",
diff --git a/i18n/ve-mw/en.json b/i18n/ve-mw/en.json
index 946eab5508..4bbb3697a3 100644
--- a/i18n/ve-mw/en.json
+++ b/i18n/ve-mw/en.json
@@ -213,6 +213,7 @@
 	"visualeditor-dialog-transclusion-param-example-long": "Example: $1",
 	"visualeditor-dialog-transclusion-param-info": "Field description",
 	"visualeditor-dialog-transclusion-param-info-missing": "No field description available",
+	"visualeditor-dialog-transclusion-param-selection-aria-description": "Press Space to add or remove parameters. Press Enter to add a parameter and immediately edit its value. When a parameter is already selected, press Enter to edit the value.",
 	"visualeditor-dialog-transclusion-param-selection-aria-label": "Parameters in $1",
 	"visualeditor-dialog-transclusion-param-undocumented": "(Undocumented parameter)",
 	"visualeditor-dialog-transclusion-placeholder": "Add a template",
diff --git a/i18n/ve-mw/qqq.json b/i18n/ve-mw/qqq.json
index 9b85bac342..36776cb83f 100644
--- a/i18n/ve-mw/qqq.json
+++ b/i18n/ve-mw/qqq.json
@@ -231,6 +231,7 @@
 	"visualeditor-dialog-transclusion-param-example-long": "Label for parameter's example value in the template dialog. If feasible without abbreviation. $1 - Parameter's example value.\n{{Identical|Example}}",
 	"visualeditor-dialog-transclusion-param-info": "Title of button that hides and shows parameter descriptions",
 	"visualeditor-dialog-transclusion-param-info-missing": "Title of button that hides and shows parameter descriptions when no description is available",
+	"visualeditor-dialog-transclusion-param-selection-aria-description": "ARIA description for screen readers on the template parameter selection menu for the keyboard controls.",
 	"visualeditor-dialog-transclusion-param-selection-aria-label": "ARIA label for screen readers on template parameter selection menu.\n\nParameters:\n* $1 - The title of the related template.",
 	"visualeditor-dialog-transclusion-param-undocumented": "Label shown next to a parameter's name indicating that the parameter is undocumented.",
 	"visualeditor-dialog-transclusion-placeholder": "Label for section with options for adding a new template to a multi part transclusion.\n{{Identical|Add template}}",
diff --git a/modules/ve-mw/ui/ve.ui.MWAriaDescribe.js b/modules/ve-mw/ui/ve.ui.MWAriaDescribe.js
new file mode 100644
index 0000000000..7cd76f7f46
--- /dev/null
+++ b/modules/ve-mw/ui/ve.ui.MWAriaDescribe.js
@@ -0,0 +1,44 @@
+/**
+ * Mixin for adding descriptive ARIA support to elements.
+ *
+ * @class
+ * @abstract
+ *
+ * @constructor
+ * @param {Object} [config] Configuration options
+ * @cfg {string} [ariaDescriptionId]
+ * @cfg {string} [ariaLabel]
+ */
+ve.ui.MWAriaDescribe = function VeUiMWAriaDescribe( config ) {
+	if ( config.ariaDescriptionId ) {
+		this.setAriaDescriptionId( config.ariaDescriptionId );
+	}
+
+	if ( config.ariaLabel ) {
+		this.setAriaLabel( config.ariaLabel );
+	}
+};
+
+/* Setup */
+
+OO.initClass( ve.ui.MWAriaDescribe );
+
+/**
+ * @param {string} id
+ * @chainable
+ * @return {OO.ui.Element} The element, for chaining
+ */
+ve.ui.MWAriaDescribe.prototype.setAriaDescriptionId = function ( id ) {
+	this.$element.attr( 'aria-describedby', id );
+	return this;
+};
+
+/**
+ * @param {string} label
+ * @chainable
+ * @return {OO.ui.Element} The element, for chaining
+ */
+ve.ui.MWAriaDescribe.prototype.setAriaLabel = function ( label ) {
+	this.$element.attr( 'aria-label', label );
+	return this;
+};
diff --git a/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineParameterSelectWidget.js b/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineParameterSelectWidget.js
index 56bb5b4a72..5c02ab81f5 100644
--- a/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineParameterSelectWidget.js
+++ b/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineParameterSelectWidget.js
@@ -19,6 +19,7 @@ ve.ui.MWTransclusionOutlineParameterSelectWidget = function VeUiMWTransclusionOu
 	OO.ui.mixin.TabIndexedElement.call( this, {
 		tabIndex: this.isEmpty() ? -1 : 0
 	} );
+	ve.ui.MWAriaDescribe.call( this, config );
 
 	this.$element
 		.on( {
@@ -33,6 +34,7 @@ ve.ui.MWTransclusionOutlineParameterSelectWidget = function VeUiMWTransclusionOu
 
 OO.inheritClass( ve.ui.MWTransclusionOutlineParameterSelectWidget, OO.ui.SelectWidget );
 OO.mixinClass( ve.ui.MWTransclusionOutlineParameterSelectWidget, OO.ui.mixin.TabIndexedElement );
+OO.mixinClass( ve.ui.MWTransclusionOutlineParameterSelectWidget, ve.ui.MWAriaDescribe );
 
 /* Events */
 
diff --git a/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineTemplateWidget.js b/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineTemplateWidget.js
index 24f33e2c1e..7b39160a79 100644
--- a/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineTemplateWidget.js
+++ b/modules/ve-mw/ui/widgets/ve.ui.MWTransclusionOutlineTemplateWidget.js
@@ -52,20 +52,26 @@ ve.ui.MWTransclusionOutlineTemplateWidget = function VeUiMWTransclusionOutlineTe
 		classes: [ 've-ui-mwTransclusionOutlineTemplateWidget-no-match' ]
 	} ).toggle( false );
 
+	var $parametersAriaDescription = $( '<span>' )
+		.text( ve.msg( 'visualeditor-dialog-transclusion-param-selection-aria-description' ) )
+		.attr( 'id', OO.ui.generateElementId() )
+		.addClass( 've-ui-mwTransclusionOutline-ariaHidden' );
+
 	this.parameters = new ve.ui.MWTransclusionOutlineParameterSelectWidget( {
-		items: parameterNames.map( this.createCheckbox.bind( this ) )
+		items: parameterNames.map( this.createCheckbox.bind( this ) ),
+		ariaLabel: ve.msg( 'visualeditor-dialog-transclusion-param-selection-aria-label', spec.getLabel() ),
+		ariaDescriptionId: $parametersAriaDescription.attr( 'id' )
 	} )
 		.connect( this, {
 			choose: 'onTemplateParameterChoose',
 			templateParameterSelectionChanged: 'onTemplateParameterSelectionChanged',
 			change: 'onParameterWidgetListChanged'
 		} );
-	this.parameters.$element
-		.attr( 'aria-label', ve.msg( 'visualeditor-dialog-transclusion-param-selection-aria-label', spec.getLabel() ) );
 
 	this.$element.append(
 		this.searchWidget.$element,
 		this.infoWidget.$element,
+		$parametersAriaDescription,
 		this.parameters.$element
 	);
 };