How would recruiters describe my job?

My company would describe you as working in "product management" as a "product management specialist" or a "product web specialist." So, similiar to what dayintoday and xingcat are saying. In the organizations I've been a part of, your tasks sound like product management responsibilities (except for writing product descriptions, which is kind of a marketing thing). As my company explains it, product development puts a product together and builds it from scratch. Product management essentially prepares a product to be sold by packaging it, preparing product information, pulling together info on specs that can be sold, etc. Marketing and sales then get out there and sells it.

I'd call that E-Commerce Content Manager, Web Content Specialist, or some combination of those terms.

Depending on the type of organization, some of those tasks might fall on a E-Commerce Merchandising Assistant. Merchandising might be responsible for providing/formatting the data, but that work then expands into the buying end of the process. Sounds like you are more on the content side, though. I would suggest E-Commerce Content Manager or E-Commerce Site Manager. Those roles are more specific to what you might be looking for, because they're going to have more exposure to the "other" things that you outlined (newsletters, social media promotion).

Seconding ch1x0r that in my experience this would not be called "product manager". You're doing a lot of different tasks that in larger organizations would usually be split across several roles, so it's difficult to match a single title to it (and tbh it may be difficult to find a similar generalist role elsewhere)... Something like content developer or content editor might be closest.

My girlfriend does much of this, minus the IT stuff, and her job title is "assistant category manager" for a particular category of products at a national retail chain.

I have seen exactly this job described as "Product Portfolio Developer."

That role falls under merchandising or design in my experience. In my company the merchandising team owns this function, but other companies might put it under copywriting/marketing. There are clearly places that call this "product management" based on comments here. In my world "product management" is responsible for determining feature roadmaps for the company and helping cross-functional efforts (like, new features on a website, etc). Not this at all. So just be aware that lots of jobs looking for "product managers" are not looking for what you do.

Sorry I didn't directly answer the question. Where I am, that job falls under the title "merchandising assistant".

I don't know what your job would be called, but make sure your resume incudes relevant keywords - I don't know all of them but I imagine that content management, ecommerce, merchandsing, etc. And if you are familiar with any systems in particular, make sure you mention those.