You can enable the description of the products on the collection & search page by going through the following steps.
Go to your Shopify Admin Store > App > Search.
Click on Search & Collection Page.
Click on Content.
Now scroll down and you will see a dropdown Max description strings.
Select the number of lines of the description you want to show under a product else choose 0 to hide the description.
Now click Save.
Please see this example for reference:
Collection & Search page without Product Description.
Collection & Search page with Product Description.