My experience:
I received an email from the recruiter to set up the time for the initial call, but he did not inform me what I was interviewing for until I followed up with him twice. Keep in mind that the recruiter sent me a link to a Google Hangout, so I was under the impression that this would be a video call.
On the day of the interview, I joined the link and waited 10 minutes for the recruiter to show up. However, I ended up getting a call instead from a recruiter that was clearly not prepared for the interview. I could clearly hear that she was driving in her car, and her questions weren't organized at all. Towards the end of the call, she said that she would be moving me on with the interview process and that I can expect an email from her to set up the times within the next couple of days. Two days later, I received an email from her stating that I would not be moving on in the interview process.
Please make sure you focus on actually putting in the time and effort to interview people, and DON'T sent mixed signals.