Maybe you'd have got away with it if it were just your first chapter that was 'a bit busy'. A pitch, has to be very straightforward, just a quick, general overview of the story, think elevator pitch. First chapter is a bit more difficult. In an ideal world, all of our first chapters would simply set the scene and show an agent how well we can write. Unfortunately all books are different, and the first chapter will depend on the pace of the rest of the book. However, I do know that a lot of us tend to try and cram too much into the first chapter, an information overload isn't good and won't do us any favours with a potential agent. He'll just get confused and bored. Difficult to get right, but not impossible, we just have to be clever and the best way I've found is to find out what the agent already publishes, and then read as many opening chapters as you can from those authors. You will soon see a pattern. Good advice!