Pinterest blocks any product row where the description field is empty. Error 107 is one of the most common reasons large catalogs lose 20-30% of their inventory at ingestion.
Description is required even though many merchants treat it as optional. Common causes: short-form Shopify products that only carry a title, BigCommerce stores using meta_description instead of description, and feeds copied from Google Shopping where description was left blank because Google can fall back to the landing page. Pinterest does not crawl the landing page to fill in gaps.