diff --git a/framework/yii/debug/panels/ConfigPanel.php b/framework/yii/debug/panels/ConfigPanel.php
index fb128b9..36fb872 100644
--- a/framework/yii/debug/panels/ConfigPanel.php
+++ b/framework/yii/debug/panels/ConfigPanel.php
@@ -12,6 +12,8 @@ use yii\debug\Panel;
 use yii\helpers\Html;
 
 /**
+ * Debugger panel that collects and displays application configuration and environment.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
diff --git a/framework/yii/debug/panels/DbPanel.php b/framework/yii/debug/panels/DbPanel.php
index b7a8afa..e047f8d 100644
--- a/framework/yii/debug/panels/DbPanel.php
+++ b/framework/yii/debug/panels/DbPanel.php
@@ -12,6 +12,8 @@ use yii\log\Logger;
 use yii\helpers\Html;
 
 /**
+ * Debugger panel that collects and displays database queries performed.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
diff --git a/framework/yii/debug/panels/LogPanel.php b/framework/yii/debug/panels/LogPanel.php
index e84bec2..b1ad63d 100644
--- a/framework/yii/debug/panels/LogPanel.php
+++ b/framework/yii/debug/panels/LogPanel.php
@@ -14,6 +14,8 @@ use yii\log\Logger;
 use yii\log\Target;
 
 /**
+ * Debugger panel that collects and displays logs.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
diff --git a/framework/yii/debug/panels/ProfilingPanel.php b/framework/yii/debug/panels/ProfilingPanel.php
index c09108e..0d3ac9d 100644
--- a/framework/yii/debug/panels/ProfilingPanel.php
+++ b/framework/yii/debug/panels/ProfilingPanel.php
@@ -13,6 +13,8 @@ use yii\helpers\Html;
 use yii\log\Logger;
 
 /**
+ * Debugger panel that collects and displays performance profiling info.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
diff --git a/framework/yii/debug/panels/RequestPanel.php b/framework/yii/debug/panels/RequestPanel.php
index 4a4a484..f8bec5d 100644
--- a/framework/yii/debug/panels/RequestPanel.php
+++ b/framework/yii/debug/panels/RequestPanel.php
@@ -13,6 +13,8 @@ use yii\debug\Panel;
 use yii\helpers\Html;
 
 /**
+ * Debugger panel that collects and displays request data.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */