My bosses have written back, and this is what I'm allowed to say about my job: I am "evaluating the relevance of web pages [to a given search] based on the scale that Google provides." If, for instance, someone searches for Yaphet Kotto, and Google returns a page of blender attachments, I will tell them that something is not quite right. (Because the only possible interpretation for that query is
here.)
I've been working for a couple of days now, two or three hours a day, and the queries are varied and interesting; it's significantly more fun than, say, data entry, and not particularly more taxing. I stress a little that I'm not going as quickly as they might expect me to, but I expect I'll get faster with time.
Thanks again to
jedediah for the pointer!