diff --git a/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php b/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php
index f711268bc7930..0fa4b919c40fa 100644
--- a/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php
+++ b/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php
@@ -7,16 +7,24 @@
 
 /**
  * Interface StockRegistryProviderInterface
+ *
+ * @deprecated 2.3.0 Replaced with Multi Source Inventory
+ * @link https://devdocs.magento.com/guides/v2.3/inventory/index.html
+ * @link https://devdocs.magento.com/guides/v2.3/inventory/catalog-inventory-replacements.html
  */
 interface StockRegistryProviderInterface
 {
     /**
+     * Get stock.
+     *
      * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockInterface
      */
     public function getStock($scopeId);
 
     /**
+     * Get stock item.
+     *
      * @param int $productId
      * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockItemInterface
@@ -24,6 +32,8 @@ public function getStock($scopeId);
     public function getStockItem($productId, $scopeId);
 
     /**
+     * Get stock status.
+     *
      * @param int $productId
      * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockStatusInterface
diff --git a/app/code/Magento/CatalogInventory/Model/Spi/StockStateProviderInterface.php b/app/code/Magento/CatalogInventory/Model/Spi/StockStateProviderInterface.php
index 89fb54e7e496b..30f703b5b928f 100644
--- a/app/code/Magento/CatalogInventory/Model/Spi/StockStateProviderInterface.php
+++ b/app/code/Magento/CatalogInventory/Model/Spi/StockStateProviderInterface.php
@@ -9,22 +9,32 @@
 
 /**
  * Interface StockStateProviderInterface
+ *
+ * @deprecated 2.3.0 Replaced with Multi Source Inventory
+ * @link https://devdocs.magento.com/guides/v2.3/inventory/index.html
+ * @link https://devdocs.magento.com/guides/v2.3/inventory/catalog-inventory-replacements.html
  */
 interface StockStateProviderInterface
 {
     /**
+     * Verify stock.
+     *
      * @param StockItemInterface $stockItem
      * @return bool
      */
     public function verifyStock(StockItemInterface $stockItem);
 
     /**
+     * Verify notification.
+     *
      * @param StockItemInterface $stockItem
      * @return bool
      */
     public function verifyNotification(StockItemInterface $stockItem);
 
     /**
+     * Validate quote qty.
+     *
      * @param StockItemInterface $stockItem
      * @param int|float $itemQty
      * @param int|float $qtyToCheck
@@ -44,8 +54,9 @@ public function checkQuoteItemQty(StockItemInterface $stockItem, $itemQty, $qtyT
     public function checkQty(StockItemInterface $stockItem, $qty);
 
     /**
-     * Returns suggested qty that satisfies qty increments and minQty/maxQty/minSaleQty/maxSaleQty conditions
-     * or original qty if such value does not exist
+     * Returns suggested qty or original qty if such value does not exist.
+     *
+     * Suggested qty satisfies qty increments and minQty/maxQty/minSaleQty/maxSaleQty conditions.
      *
      * @param StockItemInterface $stockItem
      * @param int|float $qty
@@ -54,6 +65,8 @@ public function checkQty(StockItemInterface $stockItem, $qty);
     public function suggestQty(StockItemInterface $stockItem, $qty);
 
     /**
+     * Check qty increments.
+     *
      * @param StockItemInterface $stockItem
      * @param int|float $qty
      * @return \Magento\Framework\DataObject