well, it's arguable that you are searching, and so the fact that various search providers will see your search term is not unexpected. Most people will have no idea what search tools they will end up using, but after the first time they use it (and get results back from Amazon), I don't think there will be any doubt that it includes sending the query to Amazon. I also don't think that any amount of labelling of this would noticeably change the number of people who are surprised by this the first time (people don't read documentation and release notes)
some people will like this, some will not. It's a discussion worth having on those grounds, but labelling it 'spyware' is going too far.