diff --git a/src/Plugin/HeaderAppendPlugin.php b/src/Plugin/HeaderAppendPlugin.php
index f9db2e9..1e7b320 100644
--- a/src/Plugin/HeaderAppendPlugin.php
+++ b/src/Plugin/HeaderAppendPlugin.php
@@ -6,7 +6,8 @@
 use Psr\Http\Message\RequestInterface;
 
 /**
- * Adds headers to the request.
+ * Append headers to the request.
+ *
  * If the header already exists the value will be appended to the current value.
  *
  * This only makes sense for headers that can have multiple values like 'Forwarded'
@@ -23,7 +24,7 @@ final class HeaderAppendPlugin implements Plugin
     private $headers = [];
 
     /**
-     * @param array $headers headers to add to the request
+     * @param array $headers Hashmap of header name to header value
      */
     public function __construct(array $headers)
     {
diff --git a/src/Plugin/HeaderDefaultsPlugin.php b/src/Plugin/HeaderDefaultsPlugin.php
index fcfa1ed..6dfc111 100644
--- a/src/Plugin/HeaderDefaultsPlugin.php
+++ b/src/Plugin/HeaderDefaultsPlugin.php
@@ -6,7 +6,8 @@
 use Psr\Http\Message\RequestInterface;
 
 /**
- * Set default values for the request headers.
+ * Set header to default value if it does not exist.
+ *
  * If a given header already exists the value wont be replaced and the request wont be changed.
  *
  * @author Soufiane Ghzal <sghzal@gmail.com>
@@ -19,7 +20,7 @@ final class HeaderDefaultsPlugin implements Plugin
     private $headers = [];
 
     /**
-     * @param array $headers headers to set to the request
+     * @param array $headers Hashmap of header name to header value
      */
     public function __construct(array $headers)
     {
diff --git a/src/Plugin/HeaderRemovePlugin.php b/src/Plugin/HeaderRemovePlugin.php
index 74be14f..fc9c19d 100644
--- a/src/Plugin/HeaderRemovePlugin.php
+++ b/src/Plugin/HeaderRemovePlugin.php
@@ -18,7 +18,7 @@ final class HeaderRemovePlugin implements Plugin
     private $headers = [];
 
     /**
-     * @param array $headers headers to remove from the request
+     * @param array $headers List of header names to remove from the request
      */
     public function __construct(array $headers)
     {
diff --git a/src/Plugin/HeaderSetPlugin.php b/src/Plugin/HeaderSetPlugin.php
index f1b38d0..75f11d4 100644
--- a/src/Plugin/HeaderSetPlugin.php
+++ b/src/Plugin/HeaderSetPlugin.php
@@ -6,7 +6,8 @@
 use Psr\Http\Message\RequestInterface;
 
 /**
- * Set headers to the request.
+ * Set headers on the request.
+ *
  * If the header does not exist it wil be set, if the header already exists it will be replaced.
  *
  * @author Soufiane Ghzal <sghzal@gmail.com>
@@ -19,7 +20,7 @@ final class HeaderSetPlugin implements Plugin
     private $headers = [];
 
     /**
-     * @param array $headers headers to set to the request
+     * @param array $headers Hashmap of header name to header value
      */
     public function __construct(array $headers)
     {