If the triggered ability can't determine the information it needs, or if it can't find the objects it expects to find in certain zones, those parts of the effect just do nothing
If you have enough mana and unblocked attackers, you can activate the library ninjutsu abilities of multiple Panglacial Shinobi during a single search effect
But it wasn't really until Invasion that the occasional flirting with gold cards and mechanics really came into its own and the real power of gold cards was unleashed, alongside split cards and later hybrid
Tireless Tracker and Elmar, Ulvenwald Informant can give you the Clue tokens needed for the time lord doctors ability
Note that if a spell had no other effect except to draw you one card (such as Reach Through Mists), then it would not provide card advantage
It costs a hefty 6 mana, but you immediately get a 5/5 menace haste and trample creature and an incredible sacrifice trigger on attacks