diff --git a/app/code/Magento/Eav/Api/AttributeOptionManagementInterface.php b/app/code/Magento/Eav/Api/AttributeOptionManagementInterface.php
index 5359230c08c2a..9f7dc16968064 100644
--- a/app/code/Magento/Eav/Api/AttributeOptionManagementInterface.php
+++ b/app/code/Magento/Eav/Api/AttributeOptionManagementInterface.php
@@ -13,38 +13,44 @@
 interface AttributeOptionManagementInterface
 {
     /**
-     * Add option to attribute
+     * Add an option to attribute
      *
-     * @param int $entityType
+     * @param string $entityType
      * @param string $attributeCode
      * @param \Magento\Eav\Api\Data\AttributeOptionInterface $option
-     * @throws \Magento\Framework\Exception\StateException
-     * @throws \Magento\Framework\Exception\InputException
+     *
      * @return string
+     *
+     * @throws \Magento\Framework\Exception\InputException
+     * @throws \Magento\Framework\Exception\StateException
      */
-    public function add($entityType, $attributeCode, $option);
+    public function add(string $entityType, string $attributeCode, Data\AttributeOptionInterface $option): string;
 
     /**
      * Delete option from attribute
      *
-     * @param int $entityType
+     * @param string $entityType
      * @param string $attributeCode
      * @param string $optionId
+     *
+     * @return bool
+     *
      * @throws \Magento\Framework\Exception\StateException
      * @throws \Magento\Framework\Exception\InputException
      * @throws \Magento\Framework\Exception\NoSuchEntityException
-     * @return bool
      */
-    public function delete($entityType, $attributeCode, $optionId);
+    public function delete(string $entityType, string $attributeCode, string|int $optionId): bool;
 
     /**
-     * Retrieve list of attribute options
+     * Retrieve a list of attribute options
      *
-     * @param int $entityType
+     * @param string $entityType
      * @param string $attributeCode
+     *
+     * @return \Magento\Eav\Api\Data\AttributeOptionInterface[]
+     *
      * @throws \Magento\Framework\Exception\StateException
      * @throws \Magento\Framework\Exception\InputException
-     * @return \Magento\Eav\Api\Data\AttributeOptionInterface[]
      */
-    public function getItems($entityType, $attributeCode);
+    public function getItems(string $entityType, string $attributeCode): array;
 }
diff --git a/app/code/Magento/Eav/Api/AttributeRepositoryInterface.php b/app/code/Magento/Eav/Api/AttributeRepositoryInterface.php
index ad323cdd7bf36..dfade958e5eab 100644
--- a/app/code/Magento/Eav/Api/AttributeRepositoryInterface.php
+++ b/app/code/Magento/Eav/Api/AttributeRepositoryInterface.php
@@ -6,6 +6,9 @@
  */
 namespace Magento\Eav\Api;
 
+use Magento\Eav\Api\Data\AttributeInterface;
+use Magento\Framework\Api\SearchCriteriaInterface;
+
 /**
  * Interface AttributeRepositoryInterface
  * @api
@@ -20,43 +23,51 @@ interface AttributeRepositoryInterface
      * @param \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
      * @return \Magento\Eav\Api\Data\AttributeSearchResultsInterface
      */
-    public function getList($entityTypeCode, \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria);
+    public function getList(
+        string $entityTypeCode,
+        SearchCriteriaInterface $searchCriteria
+    ): Data\AttributeSearchResultsInterface;
 
     /**
      * Retrieve specific attribute
      *
      * @param string $entityTypeCode
      * @param string $attributeCode
+     *
      * @return \Magento\Eav\Api\Data\AttributeInterface
+     *
      * @throws \Magento\Framework\Exception\NoSuchEntityException
      */
-    public function get($entityTypeCode, $attributeCode);
+    public function get(string $entityTypeCode, string $attributeCode): Data\AttributeInterface;
 
     /**
      * Create attribute data
      *
      * @param \Magento\Eav\Api\Data\AttributeInterface $attribute
-     * @return string
+     *
+     * @return \Magento\Eav\Api\Data\AttributeInterface
+     *
      * @throws \Magento\Framework\Exception\StateException
      */
-    public function save(\Magento\Eav\Api\Data\AttributeInterface $attribute);
+    public function save(AttributeInterface $attribute): AttributeInterface;
 
     /**
      * Delete Attribute
      *
      * @param Data\AttributeInterface $attribute
      * @return bool True if the entity was deleted
+     *
      * @throws \Magento\Framework\Exception\StateException
      */
-    public function delete(Data\AttributeInterface $attribute);
+    public function delete(Data\AttributeInterface $attribute): bool;
 
     /**
      * Delete Attribute By Id
      *
-     * @param int $attributeId
+     * @param int|string $attributeId
      * @return bool True if the entity was deleted
      * @throws \Magento\Framework\Exception\NoSuchEntityException
      * @throws \Magento\Framework\Exception\StateException
      */
-    public function deleteById($attributeId);
+    public function deleteById(int|string $attributeId): bool;
 }
diff --git a/app/code/Magento/Eav/Model/AttributeRepository.php b/app/code/Magento/Eav/Model/AttributeRepository.php
index 5bd489ca6e35a..0d6ef4820f99e 100644
--- a/app/code/Magento/Eav/Model/AttributeRepository.php
+++ b/app/code/Magento/Eav/Model/AttributeRepository.php
@@ -6,8 +6,11 @@
 
 namespace Magento\Eav\Model;
 
+use Magento\Eav\Api\Data\AttributeInterface;
+use Magento\Eav\Api\Data\AttributeSearchResultsInterface;
 use Magento\Framework\Api\SearchCriteria\CollectionProcessor;
 use Magento\Framework\Api\SearchCriteria\CollectionProcessorInterface;
+use Magento\Framework\Api\SearchCriteriaInterface;
 use Magento\Framework\Exception\InputException;
 use Magento\Framework\Exception\NoSuchEntityException;
 use Magento\Framework\Exception\StateException;
@@ -83,20 +86,24 @@ public function __construct(
     /**
      * {@inheritdoc}
      */
-    public function save(\Magento\Eav\Api\Data\AttributeInterface $attribute)
+    public function save(AttributeInterface $attribute): AttributeInterface
     {
         try {
             $this->eavResource->save($attribute);
         } catch (\Exception $e) {
             throw new StateException(__("The attribute can't be saved."), $e);
         }
+
         return $attribute;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function getList($entityTypeCode, \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria)
+    public function getList(
+        string $entityTypeCode,
+        SearchCriteriaInterface $searchCriteria
+    ): AttributeSearchResultsInterface
     {
         if (!$entityTypeCode) {
             throw InputException::requiredField('entity_type_code');
@@ -158,7 +165,7 @@ public function getList($entityTypeCode, \Magento\Framework\Api\SearchCriteriaIn
     /**
      * {@inheritdoc}
      */
-    public function get($entityTypeCode, $attributeCode)
+    public function get(string $entityTypeCode, string $attributeCode): AttributeInterface
     {
         /** @var \Magento\Eav\Api\Data\AttributeInterface $attribute */
         $attribute = $this->eavConfig->getAttribute($entityTypeCode, $attributeCode);
@@ -170,13 +177,14 @@ public function get($entityTypeCode, $attributeCode)
                 )
             );
         }
+
         return $attribute;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function delete(\Magento\Eav\Api\Data\AttributeInterface $attribute)
+    public function delete(AttributeInterface $attribute): bool
     {
         try {
             $this->eavResource->delete($attribute);
@@ -189,7 +197,7 @@ public function delete(\Magento\Eav\Api\Data\AttributeInterface $attribute)
     /**
      * {@inheritdoc}
      */
-    public function deleteById($attributeId)
+    public function deleteById(int|string $attributeId): bool
     {
         /** @var \Magento\Eav\Model\Entity\Attribute $attribute */
         $attribute = $this->attributeFactory->create();
@@ -211,13 +219,14 @@ public function deleteById($attributeId)
      * @deprecated 101.0.0
      * @return CollectionProcessorInterface
      */
-    private function getCollectionProcessor()
+    private function getCollectionProcessor(): CollectionProcessorInterface
     {
         if (!$this->collectionProcessor) {
             $this->collectionProcessor = \Magento\Framework\App\ObjectManager::getInstance()->get(
                 CollectionProcessor::class
             );
         }
+
         return $this->collectionProcessor;
     }
 }
diff --git a/app/code/Magento/Eav/Model/Entity/Attribute/OptionManagement.php b/app/code/Magento/Eav/Model/Entity/Attribute/OptionManagement.php
index 2c9b6d68b0bbf..29dc5b7b8fe10 100644
--- a/app/code/Magento/Eav/Model/Entity/Attribute/OptionManagement.php
+++ b/app/code/Magento/Eav/Model/Entity/Attribute/OptionManagement.php
@@ -46,17 +46,19 @@ public function __construct(
     }
 
     /**
-     * Add option to attribute.
+     * Add an option to attribute.
      *
-     * @param int $entityType
+     * @param string $entityType
      * @param string $attributeCode
-     * @param AttributeOptionInterface $option
+     * @param \Magento\Eav\Api\Data\AttributeOptionInterface $option
+     *
      * @return string
+     *
      * @throws InputException
      * @throws NoSuchEntityException
      * @throws StateException
      */
-    public function add($entityType, $attributeCode, $option)
+    public function add(string $entityType, string $attributeCode, AttributeOptionInterface $option): string
     {
         $attribute = $this->loadAttribute($entityType, (string)$attributeCode);
 
@@ -160,7 +162,7 @@ private function saveOption(
     }
 
     /**
-     * Get option id to create new option
+     * Get option id to create a new option
      *
      * @param AttributeOptionInterface $option
      * @return string
@@ -178,7 +180,7 @@ private function getNewOptionId(AttributeOptionInterface $option): string
     /**
      * @inheritdoc
      */
-    public function delete($entityType, $attributeCode, $optionId)
+    public function delete(string $entityType, string $attributeCode, string|int $optionId): bool
     {
         $attribute = $this->loadAttribute($entityType, $attributeCode);
         $this->validateOption($attribute, $optionId);
@@ -202,7 +204,7 @@ public function delete($entityType, $attributeCode, $optionId)
     /**
      * @inheritdoc
      */
-    public function getItems($entityType, $attributeCode)
+    public function getItems(string $entityType, string $attributeCode): array
     {
         if (empty($attributeCode)) {
             throw new InputException(__('The attribute code is empty. Enter the code and try again.'));
@@ -226,7 +228,7 @@ public function getItems($entityType, $attributeCode)
      * @return void
      * @throws NoSuchEntityException
      */
-    protected function validateOption($attribute, $optionId)
+    protected function validateOption(EavAttributeInterface $attribute, int $optionId): void
     {
         if ($attribute->getSource()->getOptionText($optionId) === false) {
             throw new NoSuchEntityException(
@@ -242,14 +244,14 @@ protected function validateOption($attribute, $optionId)
     /**
      * Load attribute
      *
-     * @param string|int $entityType
+     * @param string $entityType
      * @param string $attributeCode
      * @return EavAttributeInterface
      * @throws InputException
      * @throws NoSuchEntityException
      * @throws StateException
      */
-    private function loadAttribute($entityType, string $attributeCode): EavAttributeInterface
+    private function loadAttribute(string $entityType, string $attributeCode): EavAttributeInterface
     {
         if (empty($attributeCode)) {
             throw new InputException(__('The attribute code is empty. Enter the code and try again.'));
@@ -278,6 +280,7 @@ private function retrieveOptionId(
     ) : string {
         $label = $option->getLabel() !== null ? trim($option->getLabel()) : '';
         $optionId = $attribute->getSource()->getOptionId($label);
+
         if ($optionId) {
             $option->setValue($optionId);
         } elseif (is_array($option->getStoreLabels())) {