The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
The first thing that comes to my mind is The Cavalry. Would that work for you?
LOAD"WITTYFORUMSIGNATURE",8,1 FILE NOT FOUND ERRORStory-Breaker Power? 11th-Hour Superpower? These aren't Characters as Device tropes but they can apply when a character suddenly has the power needed to resolve the conflict.
Each situation may be its own trope. E.g. a Techno Wizard would help out the hero with exactly the digital info needed for the plot to move on. What example did you have in mind?
Depending on whether it is always the same skillset or a different one each time, you could also count that under either This Looks Like a Job for Aquaman or New Powers as the Plot Demands.
LOAD"WITTYFORUMSIGNATURE",8,1 FILE NOT FOUND ERRORAll of the above are situationally valid. The exact scenario needs to be given step-by-step because The Good Guys Always Win, so it's always expected they'll solve the plot using their mad skills.
But, like... characters solve problems in different ways. MacGyver takes down the bad guys via (spoiler alert) MacGyvering every episode, but that's not a "Story-Breaker Power" or a Deus Ex Machina just because he always manages to make a gadget out of whatever's lying around. That's his whole thing.
Each situation may be its own trope. E.g. a Techno Wizard would help out the hero with exactly the digital info needed for the plot to move on. What example did you have in mind?
There's an audio drama I listen to, Midnight Burger, which has a theoretical physicist character and an engineer character. And what I've come to observe is that the physicist is so brilliant that she can figure out whatever problem the protagonists are facing, no matter how weird or unprecedented, and the engineer is so gifted that he can make whatever gizmo they need to escape any danger in any given episode. Basically, they're given skill sets and mental traits that allow them to fix any problem the writer has created for them. Hence the question about characters serving as a Deus Ex Machina.
I suppose that might just be "character has somewhat unrealistic abilities that prove helpful," which isn't really a trope.
^ I think it’s the other way around — the characters’ skills bend over backwards to serve the needs of the plot. Like with The Main Characters Do Everything, where the team members are improbably talented in every field just so the story can move forward efficiently.

Do we have a trope to describe characters who, intentionally or otherwise, mostly serve as human Deus Ex Machinas? Basically, characters who, by dint of their particular skill set or background, always seem to have just what the team needs to solve the seemingly intractable problem the writers have created?
Fixer Sue seems close to this, but it's more of a fan-fic trope and has the "don't put on a work page at all" tag. I would assume what I'm looking for is pretty YMMV, but maybe not.