Perhaps nocodeforparanoia is getting at the intensity of Tool's sound.  I'll agree with danlowlite in that Adam Jones's artistic background gives him a sort of artiste aura that colors our evaluation of his playing style, and in general the oftentimes cryptic, occult and deep lyrics add a sense of mystery to the band.  If you go to toolshed.down.net, as danlowlite suggests, you will find tabs, but these are very basic, and are often wrong.  Sure, they have the basic melody, and most of the chords are right, but they don't capture all the variations and chord inversions that Adam Jones uses.  

     The fact that Tool is a metal band would cause many to argue that these are minor details, as this sort of purposeful complexity is too often associated with the shred style guitarists, or the guitar-god/guitar hero persona started by Jimi Hendrix, and applied through the late 80's.  Steve Vai, Joe SatrianiEric Johnson, as well as Nuno Bettencourt, John Petrucci and Reeves Gabrels are prime examples of the shred school of soloing. Dimebag Darrel, of Pantera, also embraces this sort of breakneck speed, caustic soloing, but Pantera are so heavy that it's hard to compare them to 80's shred.

    So if sheer speed of playing is the criteria we are going to hold Tool to, than this is a very one sided discussion, and we find ourselves ruling out bands simply because of the musical genre they happen to be categorized under.  Once we accept the more modern metal sound as a valid genre, consisting, like everything else, of artists of varying degrees of skill, we start to distinguish stylistic differences.  Pantera takes a more complex approach to soloing.  To carry this over to the whole band is a gross error.  They still play power chords, and they often play in dropped-D as well.  The fact that Dimebag Darrel rips up the fretboard for about a minute and a half each song doesn't make the band musical geniuses.

    The complexity of Tool lies both in the chord inversions used, as well as the texturing.  A major factor is Adam Jones tone.  The hardest part of playing Tool, assuming you have comparable technical abilities, is to sound like Tool.  This is not to say that to play Tool songs is simply a question of having enough money to afford kick-ass equipment, but also the know how to get these tones.  Having said that, one could argue that this makes Tool simply one of many studio bands, or bands that, while in the studio, create these wonderfully rich and complex songs, but cannot reproduce them live, as they have only one or two guitarists. For some odd reason, this is not the case, as Tool manage to capture this complex tone incredibly well when they play live.

    So this brings us to a dilemma.  If we accept the electric guitar as a viable instument to master, than can we consider mastery of effects and equipment to achieve a given tone artistic ability, or simply fidling with knobs. If the type of paint, and the texture of the canvas can be said to play a part in the quality of a painting, or at least in the overall aesthetic appeal, than can we parallel this to music?

    If so, than Tool are wonderfully complex, and to simply say that they're not because some people have made tabs that encompass the bare bones of the song, or that Adam doesn't play a certain number of notes per measure is simply missing the boat.  They use drop-D because they were influenced by Helmet, arguably the gods of dropped-D, and even more importantly, the use of silence in the midst of a simile or riff.  Helmet is another example of a band that is perceived as simple, because most people that tab just get the bare bones chord structure, not the inversions and complex jazz chords that the second guitar plays.  I think it is a common misconception nowadays that heavy is simple.  This is not the case, and in this new manifestation of complexity, Tool can be said to stand out from the crowd.