Toolsy is more or less the overall athletic ability a position player has (you don't hear about toolsy pitchers they simply call them athletic). A "toolsy" player is a player who can do most of the five tools at a fairly high level {hit for average, hit for power, play defense, run well and good throwing arm}. Obviously most toolsy players have a very high ceiling. Potential in it of itself is a little different. For example take say Mark Teixeira. He could do the two hitting "tools" at a very high level, but none of the others. He wasn't very "toolsy" but he had a very high ceiling. A player's ceiling to me is the type of player they can develop into if everything breaks for them and they develop. Sure it's defined by their tools to a certain extent, but tools =/= skills. A tool is something innate a player has, whether or not that tool plays is a different case. They all CERTAINLY matter a great deal because they encompass so much of what the player will develop down the road. Because we are talking about PROJECTING players five years down the road when drafting (or when they are even in Double A) we don't care about what they can do now, we care about what they're able to do down the road.