diff --git a/src/Contracts/Dispatchable.php b/src/Contracts/Dispatchable.php
index c759488..45c4406 100644
--- a/src/Contracts/Dispatchable.php
+++ b/src/Contracts/Dispatchable.php
@@ -1,12 +1,17 @@
 <?php namespace Keios\Apparatus\Contracts;
 
 
+/**
+ * Interface Dispatchable
+ * @package Keios\Apparatus\Contracts
+ */
 interface Dispatchable
 {
 
     /**
      * @fluent
-     * @param $eventName
+     *
+     * @param string $eventName
      *
      * @return Dispatchable
      */
@@ -14,6 +19,7 @@ public function name($eventName);
 
     /**
      * @fluent
+     *
      * @param $data
      *
      * @return Dispatchable
@@ -22,6 +28,7 @@ public function with($data);
 
     /**
      * @fluent
+     *
      * @param array $expectedReactions
      *
      * @return Dispatchable
diff --git a/src/Contracts/LoaderInterface.php b/src/Contracts/LoaderInterface.php
index 39da681..344efc1 100644
--- a/src/Contracts/LoaderInterface.php
+++ b/src/Contracts/LoaderInterface.php
@@ -1,7 +1,14 @@
 <?php namespace Keios\Apparatus\Contracts;
 
 
+/**
+ * Interface LoaderInterface
+ * @package Keios\Apparatus\Contracts
+ */
 interface LoaderInterface
 {
+    /**
+     * @return mixed
+     */
     public function loadScenarios();
 }
\ No newline at end of file
diff --git a/src/Contracts/Runnable.php b/src/Contracts/Runnable.php
index 367edc9..124033d 100644
--- a/src/Contracts/Runnable.php
+++ b/src/Contracts/Runnable.php
@@ -1,15 +1,38 @@
 <?php namespace Keios\Apparatus\Contracts;
 
 use Keios\Apparatus\Core\Dispatcher;
-use Keios\Apparatus\Core\Step;
 
+/**
+ * Interface Runnable
+ * @package Keios\Apparatus\Contracts
+ */
 interface Runnable
 {
+    /**
+     * @param Dispatchable $event
+     *
+     * @return mixed
+     */
     public function inject(Dispatchable $event);
 
+    /**
+     * @param Dispatcher $dispatcher
+     *
+     * @return mixed
+     */
     public function setDispatcher(Dispatcher $dispatcher);
 
+    /**
+     * @return mixed
+     */
     public function run();
 
+    /**
+     * @param string $eventName
+     * @param        $data
+     * @param array  $expectedReactions
+     *
+     * @return mixed
+     */
     public function dispatch($eventName, $data, array $expectedReactions);
 } 
\ No newline at end of file
diff --git a/src/Core/Dispatcher.php b/src/Core/Dispatcher.php
index a4aade9..c285270 100644
--- a/src/Core/Dispatcher.php
+++ b/src/Core/Dispatcher.php
@@ -34,13 +34,13 @@ public function __construct(ScenarioRepository $scenarioRepository, ScenarioRunn
      * @param \Keios\Apparatus\Contracts\Dispatchable $event
      *
      * @return mixed
+     * @throws \Keios\Apparatus\Exceptions\InvalidScenarioException
+     * @throws \Keios\Apparatus\Exceptions\NoHandlerScenarioFoundException
      */
     public function dispatch(Dispatchable $event)
     {
         $scenario = $this->scenarioRepository->findHandlerScenarioFor($event);
 
-        $reaction = $this->scenarioRunner->run($scenario, $event);
-
-        return $reaction;
+        return $this->scenarioRunner->run($scenario, $event);
     }
 } 
\ No newline at end of file
diff --git a/src/Core/Event.php b/src/Core/Event.php
index 0bc1f11..287708a 100644
--- a/src/Core/Event.php
+++ b/src/Core/Event.php
@@ -54,7 +54,7 @@ public function name($eventName)
     /**
      * @fluent
      *
-     * @param $eventName
+     * @param string $eventName
      *
      * @return \Keios\Apparatus\Contracts\Dispatchable $this
      */
@@ -94,6 +94,7 @@ public function expect(array $expectedReactions)
 
     /**
      * @return mixed
+     * @throws \Keios\Apparatus\Exceptions\NoHandlerScenarioFoundException
      */
     public function getReaction()
     {
@@ -102,7 +103,7 @@ public function getReaction()
     }
 
     /**
-     * @return mixed
+     * @return string|null
      */
     public function getEventName()
     {
diff --git a/src/Core/Scenario.php b/src/Core/Scenario.php
index 1ff9714..f6fcef8 100644
--- a/src/Core/Scenario.php
+++ b/src/Core/Scenario.php
@@ -65,6 +65,8 @@ public function __construct()
 
     /**
      * @param \Keios\Apparatus\Core\Dispatcher $dispatcher
+     *
+     * @return mixed|void
      */
     public function setDispatcher(Dispatcher $dispatcher)
     {
@@ -73,6 +75,8 @@ public function setDispatcher(Dispatcher $dispatcher)
 
     /**
      * @param \Keios\Apparatus\Contracts\Dispatchable $event
+     *
+     * @return mixed|void
      */
     public function inject(Dispatchable $event)
     {
@@ -117,6 +121,9 @@ public function has($property)
 
     /**
      * @return mixed
+     * @throws \Keios\Apparatus\Exceptions\NoStepForEventFoundException
+     * @throws \Keios\Apparatus\Exceptions\NotInitializedException
+     * @throws \Keios\Apparatus\Exceptions\NoStepsDefinedException
      */
     public function run()
     {
@@ -143,9 +150,9 @@ public function run()
     }
 
     /**
-     * @param       $eventName
-     * @param       $data
-     * @param array $expectedReactions
+     * @param string $eventName
+     * @param        $data
+     * @param array  $expectedReactions
      *
      * @return mixed
      */
@@ -158,6 +165,9 @@ public function dispatch($eventName, $data, array $expectedReactions)
 
     /**
      * @param \Keios\Apparatus\Core\Step $step
+     *
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
+     * @throws \Keios\Apparatus\Exceptions\StepAlreadyRegisteredException
      */
     public function add(Step $step)
     {
@@ -168,6 +178,9 @@ public function add(Step $step)
     /**
      * @param                            $stepName
      * @param \Keios\Apparatus\Core\Step $step
+     *
+     * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
      */
     public function replace($stepName, Step $step)
     {
@@ -177,6 +190,9 @@ public function replace($stepName, Step $step)
     /**
      * @param                            $stepName
      * @param \Keios\Apparatus\Core\Step $step
+     *
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
+     * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
      */
     public function insertBefore($stepName, Step $step)
     {
@@ -186,6 +202,9 @@ public function insertBefore($stepName, Step $step)
     /**
      * @param                            $stepName
      * @param \Keios\Apparatus\Core\Step $step
+     *
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
+     * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
      */
     public function insertAfter($stepName, Step $step)
     {
diff --git a/src/Core/ScenarioConfiguration.php b/src/Core/ScenarioConfiguration.php
index 35f02a3..3d873b3 100644
--- a/src/Core/ScenarioConfiguration.php
+++ b/src/Core/ScenarioConfiguration.php
@@ -18,8 +18,8 @@ class ScenarioConfiguration implements LoaderInterface
     protected $registeredScenarios = [];
 
     /**
-     * @param $eventName
-     * @param $scenarioClassName
+     * @param string $eventName
+     * @param string $scenarioClassName
      *
      * @throws \Keios\Apparatus\Exceptions\InvalidScenarioException
      * @throws \Keios\Apparatus\Exceptions\ScenarioNotFoundException
@@ -38,7 +38,7 @@ public function bind($eventName, $scenarioClassName)
     }
 
     /**
-     * @param $scenarioClassName
+     * @param string $scenarioClassName
      *
      * @throws \Keios\Apparatus\Exceptions\ScenarioNotFoundException
      */
@@ -52,7 +52,7 @@ protected function assertScenarioExists($scenarioClassName)
     }
 
     /**
-     * @param $scenarioClassName
+     * @param string $scenarioClassName
      *
      * @throws \Keios\Apparatus\Exceptions\InvalidScenarioException
      */
diff --git a/src/Core/ScenarioFactory.php b/src/Core/ScenarioFactory.php
index 7ef16b2..b30b4ce 100644
--- a/src/Core/ScenarioFactory.php
+++ b/src/Core/ScenarioFactory.php
@@ -32,6 +32,7 @@ public function __construct(LoaderInterface $scenarioLoader)
      * @param \Keios\Apparatus\Contracts\Dispatchable $event
      *
      * @return mixed
+     * @throws \Keios\Apparatus\Exceptions\InvalidScenarioException
      * @throws \Keios\Apparatus\Exceptions\NoHandlerScenarioFoundException
      */
     public function findHandlerScenarioFor(Dispatchable $event)
@@ -44,7 +45,7 @@ public function findHandlerScenarioFor(Dispatchable $event)
     }
 
     /**
-     * @param $eventName
+     * @param string $eventName
      *
      * @return bool
      */
@@ -93,11 +94,9 @@ protected function make($eventName)
     protected function resolveClosure($closure)
     {
         $scenario = $closure();
-
-        if ($interfaces = class_implements($scenario)) {
-            if (in_array('Keios\Apparatus\Contracts\Runnable', $interfaces)) {
+        $interfaces = class_implements($scenario);
+        if ($interfaces && in_array('Keios\Apparatus\Contracts\Runnable', $interfaces, true)) {
                 return is_object($scenario) ? $scenario : new $scenario();
-            }
         }
 
         throw new InvalidScenarioException(
@@ -106,7 +105,7 @@ protected function resolveClosure($closure)
     }
 
     /**
-     * @param $eventName
+     * @param string $eventName
      *
      * @throws \Keios\Apparatus\Exceptions\NoHandlerScenarioFoundException
      */
diff --git a/src/Core/ScenarioRepository.php b/src/Core/ScenarioRepository.php
index 570bb93..fecb539 100644
--- a/src/Core/ScenarioRepository.php
+++ b/src/Core/ScenarioRepository.php
@@ -31,6 +31,8 @@ public function __construct(ScenarioFactory $scenarioFactory)
      * @param \Keios\Apparatus\Contracts\Dispatchable $event
      *
      * @return mixed
+     * @throws \Keios\Apparatus\Exceptions\InvalidScenarioException
+     * @throws \Keios\Apparatus\Exceptions\NoHandlerScenarioFoundException
      */
     public function findHandlerScenarioFor(Dispatchable $event)
     {
diff --git a/src/Core/ScenarioRunner.php b/src/Core/ScenarioRunner.php
index 6b9514b..e65270d 100644
--- a/src/Core/ScenarioRunner.php
+++ b/src/Core/ScenarioRunner.php
@@ -11,7 +11,7 @@
 class ScenarioRunner
 {
     /**
-     * @var
+     * @var Dispatcher
      */
     protected $dispatcher;
 
diff --git a/src/Core/ScenarioStepsList.php b/src/Core/ScenarioStepsList.php
index 407e78c..66e270b 100644
--- a/src/Core/ScenarioStepsList.php
+++ b/src/Core/ScenarioStepsList.php
@@ -33,7 +33,7 @@ class ScenarioStepsList
     /**
      * @var null|Step
      */
-    protected $currentStep = null;
+    protected $currentStep;
 
     /**
      * @var \Keios\Apparatus\Contracts\Runnable
@@ -52,6 +52,7 @@ public function __construct(Runnable $scenario)
      * @param $eventName
      *
      * @throws \Keios\Apparatus\Exceptions\NoStepsDefinedException
+     * @throws \Keios\Apparatus\Exceptions\NoStepForEventFoundException
      */
     public function initialize($eventName)
     {
@@ -117,6 +118,7 @@ public function getPreviousStep()
 
     /**
      * @return bool
+     * @throws \Keios\Apparatus\Exceptions\NotInitializedException
      */
     public function hasNextStep()
     {
@@ -125,6 +127,7 @@ public function hasNextStep()
 
     /**
      * @return bool
+     * @throws \Keios\Apparatus\Exceptions\NotInitializedException
      */
     public function hasPreviousStep()
     {
@@ -132,7 +135,7 @@ public function hasPreviousStep()
     }
 
     /**
-     *
+     * @throws \Keios\Apparatus\Exceptions\NotInitializedException
      */
     public function moveToNextStep()
     {
@@ -141,7 +144,7 @@ public function moveToNextStep()
     }
 
     /**
-     *
+     * @throws \Keios\Apparatus\Exceptions\NotInitializedException
      */
     public function moveToPreviousStep()
     {
@@ -150,7 +153,7 @@ public function moveToPreviousStep()
     }
 
     /**
-     * @param $stepName
+     * @param string $stepName
      *
      * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
      */
@@ -177,7 +180,7 @@ public function add(Step $step)
     }
 
     /**
-     * @param $stepName
+     * @param string $stepName
      *
      * @return bool
      */
@@ -187,7 +190,7 @@ public function hasStepNamed($stepName)
     }
 
     /**
-     * @param $eventName
+     * @param string $eventName
      *
      * @return mixed
      * @throws \Keios\Apparatus\Exceptions\NoStepForEventFoundException
@@ -200,8 +203,11 @@ public function getStepForEvent($eventName)
     }
 
     /**
-     * @param                            $stepName
+     * @param string                     $stepName
      * @param \Keios\Apparatus\Core\Step $step
+     *
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
+     * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
      */
     public function insertAfter($stepName, Step $step)
     {
@@ -209,8 +215,11 @@ public function insertAfter($stepName, Step $step)
     }
 
     /**
-     * @param                            $stepName
+     * @param string                     $stepName
      * @param \Keios\Apparatus\Core\Step $step
+     *
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
+     * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
      */
     public function insertBefore($stepName, Step $step)
     {
@@ -218,10 +227,11 @@ public function insertBefore($stepName, Step $step)
     }
 
     /**
-     * @param                            $stepNameToReplace
+     * @param string                     $stepNameToReplace
      * @param \Keios\Apparatus\Core\Step $replacingStep
      *
      * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
+     * @throws \Keios\Apparatus\Exceptions\EventAlreadyRegisteredException
      */
     public function replace($stepNameToReplace, Step $replacingStep)
     {
@@ -247,7 +257,7 @@ public function replace($stepNameToReplace, Step $replacingStep)
     }
 
     /**
-     * @param                            $stepName
+     * @param string                     $stepName
      * @param \Keios\Apparatus\Core\Step $step
      * @param bool                       $after
      *
@@ -311,7 +321,7 @@ protected function assertUniqueEventBinding(array $eventNames)
     }
 
     /**
-     * @param $stepName
+     * @param string $stepName
      *
      * @throws \Keios\Apparatus\Exceptions\StepAlreadyRegisteredException
      */
@@ -325,7 +335,7 @@ protected function assertUniqueStepName($stepName)
     }
 
     /**
-     * @param $eventName
+     * @param string $eventName
      *
      * @throws \Keios\Apparatus\Exceptions\NoStepForEventFoundException
      */
@@ -359,7 +369,7 @@ protected function assertIsInitialized()
     }
 
     /**
-     * @param $stepName
+     * @param string $stepName
      *
      * @throws \Keios\Apparatus\Exceptions\NoStepWithNameFoundException
      */
diff --git a/src/Core/SideAction.php b/src/Core/SideAction.php
index 10855d6..106420e 100644
--- a/src/Core/SideAction.php
+++ b/src/Core/SideAction.php
@@ -9,6 +9,12 @@
  */
 abstract class SideAction extends Action
 {
+    /**
+     * @param Runnable $scenario
+     * @param          $result
+     *
+     * @return mixed|void
+     */
     public function __invoke(Runnable $scenario, $result)
     {
         $this->scenario = $scenario;
diff --git a/src/Core/Step.php b/src/Core/Step.php
index 4313cdb..14a1045 100644
--- a/src/Core/Step.php
+++ b/src/Core/Step.php
@@ -15,7 +15,7 @@ class Step
     protected static $sideActionsCache = [];
 
     /**
-     * @var
+     * @var string
      */
     protected $name;
 
@@ -25,7 +25,7 @@ class Step
     protected $action;
 
     /**
-     * @var
+     * @var Runnable
      */
     protected $scenario;
 
@@ -40,7 +40,7 @@ class Step
     protected $sideActions = [];
 
     /**
-     * @param          $name
+     * @param string   $name
      * @param callable $action
      * @param array    $triggeringEvents
      */
@@ -80,7 +80,7 @@ public function __invoke($lastStepResult)
     }
 
     /**
-     * @return mixed
+     * @return string|null
      */
     public function getName()
     {
@@ -97,7 +97,9 @@ public function getTriggeringEvents()
 
     /**
      * @fluent
+     *
      * @param callable $sideAction
+     *
      * @return Step
      */
     public function with(callable $sideAction)
@@ -107,9 +109,6 @@ public function with(callable $sideAction)
         return $this;
     }
 
-    /**
-     *
-     */
     protected function importSideActions()
     {
         if (isset(static::$sideActionsCache[$this->name]) && is_array(static::$sideActionsCache[$this->name])) {
@@ -143,7 +142,7 @@ protected function executeSideActions($result)
     }
 
     /**
-     * @param          $stepName
+     * @param string   $stepName
      * @param callable $sideAction
      */
     public static function addSideAction($stepName, callable $sideAction)