Hello Friends,

The below code will help you to Customize a product tab in woo commerce using 'woocommerce_product_tabs' action hook, first you have to replace the description tab with a custom function.

  <?php
    add_filter( 'woocommerce_product_tabs', 'woo_findnerd_custom_description_tab', 8 );
    function woo_findnerd_custom_description_tab( $destabs ) {
     $destabs['description']['callback'] = 'woo_findnerd_custom_description_tab_content'; // description callback with custom function
     return $destabs;
    }
    function woo_findnerd_custom_description_tab_content() {
     echo '<h1>TYPE YOUR TITLE Here</h1>'; //
     echo '<p>TYPE YOUR DESCRIPTION HERE </p>'; //
    }
?>

In above code we are replacing default product description with our custom description.

Here woocommerce_product_tabs is an action hook function of woocommerce which holds product tab of woocommerce.
And woo_findnerd_custom_description_tab is a user defined function that you can change it according to your wish.