Inquiring minds want to know:
What image meta tag gets pulled into a pin?
Does it matter which pinning tool you use?
Your personal Pinterest Investigative Reporter to the Rescue.
I tested Pinterest’s PinIt Bookmarklet (first option on the list) on my Rugs from Rags site (better image collection) to see which of an image’s metadata fields was passed to the Description field on a pin.
It’s the Alt Tag.
When you load images to your website that you want other people to pin, make sure you have useful content in the Alt field. Some pinners will delete this and add their own description (often lame, unfortunately) but if you offer good content, you have a better chance of your words making it into the pin flow.
I’m off to review all my alt tags. (Will test other WP plugin pinning options as I come to them. I use NextGen to manage a lot of the images on Rugs from Rags and I don’t like the way any of the Pinterest plugins work with NextGen.)
I’m writing a separate post about using Pinterest’s image-specific PinIt button (third option on the list).