I’ve seen a lot of agents write blogs on the problem with giving feedback on rejections, or the answer to why they don’t give feedback. Primarily it’s a consideration for time with most agents. One I completely understand.
That being said, I do make an effort to give some sort of feedback on every partial or manuscript that I’ve requested and am subsequently rejecting. The problem with that is that the feedback I’m giving is usually not going to be nearly as comprehensive as what you need.
I’ve got a few form letters I use when giving feedback. I tend to tweak them to fit each manuscript so that what I’m saying still fits each manuscript personally. My concern with that, always, is that I think too often the feedback comes across as simplistic, giving the author the misunderstanding that it’s an easy fix and therefore the road to an easy agent.
Usually an agent’s feedback is the tip of the iceberg of what needs to be changed. In other words, you’re going to have to read between the lines a bit to see what the agent is saying specifically and what that could mean globally to your manuscript. And, of course, before you ever make any changes you need to make sure that what the agent is saying actually resonates with you because I guarantee you won’t be able to successfully revise your book unless you believe, in your heart, in the changes.