Toolbox decks are fun to play. There's nothing like the feeling when your opponent plays their Big Threat (TM), and you can answer it, turn after turn.
But toolbox decks (i.e., decks designed around ways to tutor for the cards you need, rather than relying on your mad topdeck skillz) are hard to make in Standard. Your tutors consist of Diabolic Tutor, Fabricate, Reshape, and Phyrexian Portal, and not much else. Half of what I just mentioned tutors artifacts only, and half of what's left is a one-shot, four mana spell. If you base your deck around Diabolic Tutor, you need to hit 6+ mana in a hurry, (4 for the Tutor, 2+ for the spell, because one-mana "answers" for threats are pretty thin on the ground in the days since Swords to Plowshares), even more if your opponent has Mana Leak mana up.
But there's a pretty decent (read: works in casual play, belches brown smoke from its tailpipe otherwise) tutor in the CHK block enchantment "Night Dealings":
Name: Night Dealings
Set & Rarity:
Champions of Kamigawa rare
Card Type: Enchantment
Rules Text (Oracle): Whenever a source you control deals damage to another player, put that many theft counters on Night Dealings.
2BB, Remove X theft counters from Night Dealings: Search your library for a nonland card with converted mana cost X, reveal it, and put it into your hand. Then shuffle your library.
You need consistant, repeatable ways to deal a couple of damage every turn, and Black just happens to have a number of cheap creatures with Fear:
To this I added Ferropede (unblockable, backup plan against Black/Artifact decks) and Arcbound Fiend for a little more beef. (The Fiend is a bit of a compromise. It's really a bit overcosted for this deck, but the Modular ability comes in handy to pump up a Ferropede when you need to race against a Black deck.) The other options here are: Crawling Filth (expensive, Soulshift does me no good), Dross Prowler (1 point butt, and I don't need more of that here), Painwracker Oni (no Ogres), and Woebearer (decent ability, but perhaps just a little too expensive).
Then we add 4x Night Dealings. Yeah, that's a lot, but (a) they're considered crap rares, you can get them on eBay 4/$1 sometimes; (b) the deck hasn't much point to it unless you draw one by turn 4; (c) they aren't really useless in pairs, because they all get counters. Your opponent will send a disenchant-like spell in its direction eventually, and it'd be nice to have a backup source for tools. What, people play with Echoing Calm? No, I don't think so.
Finally, toolbox contents. Go wild here, but keep it to low-CC spells. Note that both Consume Spirit and Swallowing Plague are 2-cc spells when you are searching! You could go into a splice frenzy here, and load up your library with Arcane stuff. Or special-purpose critters and spells. Or whatever you like.
So, here's my current pile (limited by what I have on MTGO at present, so there may be better cards I don't have):
1,Screams from Within
1,Stir the Grave
1,Struggle for Sanity
All those singletons are "answers" of various sorts. Most were chosen for their low cost and "instant" nature, so that with a couple counters and 5-6 mana up, I can tutor for a Lose Hope or Echoing Decay as needed. For example, Screams from Within is a brutal card against White Weenie, spirit or snake tokens, etc. You may prefer Nausea, or something else. Shattered Dreams plus Scrounge is incredible if you can grab them both at the right time.
Obviously, there are many other ways you could go. Flyers, possibly with a second color (such as White). Then you might add a full set of Circles of Protection, and tutor up the one you need.
I hope you've enjoyed this deck article, and that it launches you into a new consideration of the overlooked card "Night Dealings".