diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 515a3ea..3878139 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1719,12 +1719,17 @@ function theme_links($variables) {
           $item = drupal_render($link_element);
         }
         else {
+          // @todo theme_links() should *really* use the same parameters as l(),
+          // and just take an array of '#type' => 'link' elements.
+          // Pass in $link as $options, as they share the same keys.
           if (isset($link['href'])) {
-            // Pass in $link as $options, as they share the same keys.
             $item = l($link['title'], $link['href'], $link);
           }
           else {
-            $item = \Drupal::linkGenerator()->generate($link['title'], $link['route_name'], isset($link['route_parameters']) ? $link['route_parameters'] : array(), $link);
+            if (empty($link['route_parameters'])) {
+              $link['route_parameters'] = array();
+            }
+            $item = \Drupal::l($link['title'], $link['route_name'], $link['route_parameters'], $link);
           }
         }
       }
diff --git a/core/lib/Drupal/Core/Menu/ContextualLinkBase.php b/core/lib/Drupal/Core/Menu/ContextualLinkDefault.php
similarity index 73%
rename from core/lib/Drupal/Core/Menu/ContextualLinkBase.php
rename to core/lib/Drupal/Core/Menu/ContextualLinkDefault.php
index 454f7b0..94c46b6 100644
--- a/core/lib/Drupal/Core/Menu/ContextualLinkBase.php
+++ b/core/lib/Drupal/Core/Menu/ContextualLinkDefault.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\Core\Menu\ContextualLinkBase.
+ * Contains \Drupal\Core\Menu\ContextualLinkDefault.
  */
 
 namespace Drupal\Core\Menu;
@@ -12,13 +12,14 @@
 /**
  * Provides a common base implementation of a contextual link.
  */
-class ContextualLinkBase extends PluginBase implements ContextualLinkInterface {
+class ContextualLinkDefault extends PluginBase implements ContextualLinkInterface {
 
   /**
    * {@inheritdoc}
    */
   public function getTitle() {
-    return $this->pluginDefinition['title'];
+    // @todo use $this->t() when https://drupal.org/node/2087231 lands.
+    return t($this->pluginDefinition['title']);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Menu/ContextualLinkManager.php b/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
index 9c81a82..996339d 100644
--- a/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
+++ b/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Menu;
 
+use Drupal\Component\Plugin\Exception\PluginException;
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Controller\ControllerResolverInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
@@ -25,18 +26,25 @@
 class ContextualLinkManager extends DefaultPluginManager {
 
   /**
-   * Provides some default values for contextual links
+   * Provides default values for a contextual link definition.
    *
    * @var array
    */
   protected $defaults = array(
-    'class' => '\Drupal\Core\Menu\ContextualLinkBase',
-    'group' => '',
-    'id' => '',
-    'options' => array(),
+    // (required) The name of the route to link to.
     'route_name' => '',
+    // (required) The contextual links group.
+    'group' => '',
+    // The static title text for the link.
     'title' => '',
-    'weight' => 0,
+    // The default link options.
+    'options' => array(),
+    // The weight of the link.
+    'weight' => NULL,
+    // Default class for contextual link implementations.
+    'class' => '\Drupal\Core\Menu\ContextualLinkDefault',
+    // The plugin id. Set by the plugin system based on the top-level YAML key.
+    'id' => '',
   );
 
   /**
@@ -62,6 +70,21 @@ public function __construct(ControllerResolverInterface $controller_resolver, Mo
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function processDefinition(&$definition, $plugin_id) {
+    parent::processDefinition($definition, $plugin_id);
+     // If there is no route name, this is a broken definition.
+    if (empty($definition['route_name'])) {
+      throw new PluginException(sprintf('Plugin (%s) definition must include "route_name"', $plugin_id));
+    }
+     // If there is no group name, this is a broken definition.
+    if (empty($definition['group'])) {
+      throw new PluginException(sprintf('Plugin (%s) definition must include "group"', $plugin_id));
+    }
+  }
+
+  /**
    * Gets the contextual link plugins by contextual link group.
    *
    * @param string $group_name
diff --git a/core/modules/contextual/contextual.module b/core/modules/contextual/contextual.module
index cbf8e37..5396504 100644
--- a/core/modules/contextual/contextual.module
+++ b/core/modules/contextual/contextual.module
@@ -277,7 +277,6 @@ function contextual_pre_render_links($element) {
       'route_name' => isset($item['route_name']) ? $item['route_name'] : '',
       'route_parameters' => isset($item['route_parameters']) ? $item['route_parameters'] : array(),
     );
-    // @todo theme_links() should *really* use the same parameters as l().
     $item['localized_options'] += array('query' => array());
     $item['localized_options']['query'] += drupal_get_destination();
     $links[$class] += $item['localized_options'];
@@ -311,15 +310,14 @@ function contextual_contextual_links_view_alter(&$element, $items) {
  * Serializes #contextual_links property value array to a string.
  *
  * Examples:
- *  - node:node:1:
- *  - views_ui:admin/structure/views/view:frontpage:location=page&view_name=frontpage&view_display_id=page_1
- *  - menu:admin/structure/menu/manage:tools:|block:admin/structure/block/manage:bartik.tools:
+ *  - node:node:node=1:
+ *  - views_ui:admin/structure/views/view:view=frontpage:location=page&view_name=frontpage&view_display_id=page_1
+ *  - menu:admin/structure/menu/manage:menu=tools:|block:admin/structure/block/manage:block=bartik.tools:
  *
  * So, expressed in a pattern:
  *  <module name>:<parent path>:<path args>:<options>
  *
- * The (dynamic) path args are joined with slashes. The options are encoded as a
- * query string.
+ * The path args and options are encoded as query strings.
  *
  * @param array $contextual_links
  *   The $element['#contextual_links'] value for some render element.
@@ -329,19 +327,14 @@ function contextual_contextual_links_view_alter(&$element, $items) {
  *   use in a data- attribute.
  */
 function _contextual_links_to_id($contextual_links) {
-  $id = '';
+  $ids = array();
   foreach ($contextual_links as $module => $args) {
     $parent_path = $args[0];
-    $path_keys = implode('/', array_keys($args[1]));
-    $path_args = implode('/', $args[1]);
+    $path_args = drupal_http_build_query($args[1]);
     $metadata = drupal_http_build_query((isset($args[2])) ? $args[2] : array());
-
-    if (drupal_strlen($id) > 0) {
-      $id .= '|';
-    }
-    $id .= $module . ':' . $parent_path . ':' . $path_keys . ':' . $path_args . ':' . $metadata;
+    $ids[] = "{$module}:{$parent_path}:{$path_args}:{$metadata}";
   }
-  return $id;
+  return implode('|', $ids);
 }
 
 /**
@@ -359,14 +352,9 @@ function _contextual_id_to_links($id) {
   $contextual_links = array();
   $contexts = explode('|', $id);
   foreach ($contexts as $context) {
-    list($module, $parent_path, $path_keys, $path_args, $metadata_raw) = explode(':', $context);
-    $path_keys = explode('/', $path_keys);
-    $path_args = explode('/', $path_args);
-    foreach ($path_keys as $counter => $key) {
-      $arg = $path_args[$counter];
-      unset($path_args[$counter]);
-      $path_args[$key] = $arg;
-    }
+    list($module, $parent_path, $raw_args, $metadata_raw) = explode(':', $context);
+    $path_args = array();
+    parse_str($raw_args, $path_args);
     $metadata = array();
     parse_str($metadata_raw, $metadata);
     $contextual_links[$module] = array($parent_path, $path_args, $metadata);
diff --git a/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php b/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php
index 2ea30dc..955c0e1 100644
--- a/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php
+++ b/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualDynamicContextTest.php
@@ -60,10 +60,10 @@ function testDifferentPermissions() {
     // Now, on the front page, all article nodes should have contextual links
     // placeholders, as should the view that contains them.
     $ids = array(
-      'node:node:node:' . $node1->id() . ':',
-      'node:node:node:' . $node2->id() . ':',
-      'node:node:node:' . $node3->id() . ':',
-      'views_ui:admin/structure/views/view:0:frontpage:location=page&name=frontpage&display_id=page_1',
+      'node:node:node=' . $node1->id() . ':',
+      'node:node:node=' . $node2->id() . ':',
+      'node:node:node=' . $node3->id() . ':',
+      'views_ui:admin/structure/views/view:0=frontpage:location=page&name=frontpage&display_id=page_1',
     );
 
     // Editor user: can access contextual links and can edit articles.
diff --git a/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualUnitTest.php b/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualUnitTest.php
index e4c828d..2c93f4c 100644
--- a/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualUnitTest.php
+++ b/core/modules/contextual/lib/Drupal/contextual/Tests/ContextualUnitTest.php
@@ -39,7 +39,7 @@ function _contextual_links_id_testcases() {
           array()
         ),
       ),
-      'id' => 'node:node:node:14031991:',
+      'id' => 'node:node:node=14031991:',
     );
 
     // Test branch conditions:
@@ -58,7 +58,7 @@ function _contextual_links_id_testcases() {
           array()
         ),
       ),
-      'id' => 'foo:baz/in/ga:0/key/1:bar/baz/qux:',
+      'id' => 'foo:baz/in/ga:0=bar&key=baz&1=qux:',
     );
 
     // Test branch conditions:
@@ -76,7 +76,7 @@ function _contextual_links_id_testcases() {
           )
         ),
       ),
-      'id' => 'views_ui:admin/structure/views/view:0:frontpage:location=page&display=page_1',
+      'id' => 'views_ui:admin/structure/views/view:0=frontpage:location=page&display=page_1',
     );
 
     // Test branch conditions:
@@ -106,7 +106,7 @@ function _contextual_links_id_testcases() {
           array()
         ),
       ),
-      'id' => 'node:node:node:14031991:|foo:baz/in/ga:0/key/1:bar/baz/qux:|edge:edge:0:20011988:',
+      'id' => 'node:node:node=14031991:|foo:baz/in/ga:0=bar&key=baz&1=qux:|edge:edge:0=20011988:',
     );
 
     return $tests;