An arcane trickster can perform one of the following class skills at a range of 30 feet: Disable Device, Open Lock, or Sleight of Hand. Working at a distance increases the normal skill check DC by 5, and an arcane trickster cannot take 10 on this check. Any object to be manipulated must weigh 5 pounds or less. (DMG 178)
The restriction that you cannot use Disable Device at a distance isn't explicitly stated but clearly is implied by this prestige class ability.
The rules for Disable Device also state
Other Ways to Beat a Trap
It’s possible to ruin many traps without making a Disable Device check.
Ranged Attack Traps
Once a trap’s location is known, the obvious way to ruin it is to smash the mechanism—assuming the mechanism can be accessed. Failing that, it’s possible to plug up the holes from which the projectiles emerge. Doing this prevents the trap from firing unless its ammunition does enough damage to break through the plugs.
Melee Attack Traps
These devices can be thwarted by smashing the mechanism or blocking the weapons, as noted above. Alternatively, if a character studies the trap as it triggers, he might be able to time his dodges just right to avoid damage. A character who is doing nothing but studying a trap when it first goes off gains a +4 dodge bonus against its attacks if it is triggered again within the next minute.
Disabling a pit trap generally ruins only the trapdoor, making it an uncovered pit. Filling in the pit or building a makeshift bridge across it is an application of manual labor, not the Disable Device skill. Characters could neutralize any spikes at the bottom of a pit by attacking them—they break just as daggers do.
Dispel magic helps here. Someone who succeeds on a caster level check against the level of the trap’s creator suppresses the trap for 1d4 rounds. This works only with a targeted dispel magic, not the area version. (PH 73)
I think there's quite a bit of insinuation here that the DM should not treat a trap as an atomic unit, rather as many parts, any one of which may (or may not) effectively disable the trap if 'disabled' or smashed.
The point is; don't think of the trap as one unit, rather think about how is it triggered? what happens when it's activated? what are the mechanisms? Is it one direction? Is it the same from multiple directions? If there is an owner or inhabitants, how do they get by it? Is the bypass one switch, or multiple? How does it reset? What part or parts are detectable? Do you need multiple search DCs? Do parts of it "hide in plain sight"? Is any part magical? If so, make sure and look up detect magic and each spell involved so you can have those spellcraft DCs, schools and strengths written down in your notes.