<p>So I don't have enough room in the Activities section of the Common App to describe each EC I'm involved in. There aren't enough slots for different activities, and there's not enough room to explain each one. Could attaching a [very long] resume hurt? I can imagine that attaching a few extra pages might really annoy some readers, but I think I do have more to say.</p>
<p>You do not need to explain every activity you do in a whole lot of detail. The reason why they give you little space is so that your explanation is short. Do not attach a very long resume.</p>