What are your expectations toward agents who have submitted a manuscript to you? I didn’t have one for my country because authors approach the publishing houses directly but I now have an agent from an established firm. This agent is keen and enthusiastic for my work and always gives good advice. My agent works well with my editor here but, despite the book having received two award nominations, the response is quiet from America. Do you have agents contacting you for follow up or does that bug you. I trust my agent but I am curious cos if it were me, I’d be picking up the phone and going: have you read it yet? Look at this book – it’s fantastic!Of course agents follow up to see whether I've read it yet.
But there are plenty of editors who simply ignore such proddings (the most well-known and highest-ranking editors are often among them).
Even the most talented agents can't make an editor respond if the editor just doesn't want to. Your agent ought to be able to tell you if she's sent your manuscript to one of the usual suspects, though.