"I don't know any way to, but it's not strictly impossible that somebody could come up with one."
"...Sooooort of," he says. "I mean, I can make Devices, but there's the awareness thing if they're remotely complicated and you need a linker core to use them for most stuff I can think of... I don't know if I can make magical tools the way you mean. I'd probably have to learn conjuration if I was going to get much of anywhere with it. What kinds of things do magical tools do, besides - picture-crystal-ing?"
"Huh. Yeah... I think it's theoretically possible to make magical tools with my magic, I'm just not actually sure how you'd do it."
"I can kind of see how some of the pieces would work - how you'd make things, how you'd make things that did stuff - the main part I'm missing is how to make it so somebody without magic could use it, but just because I can't figure that part out yet doesn't mean it's impossible, it just means I'd have to think about it some more."
"A person with magic wouldn't be using a tool, they'd be accessing functions of a Device. That's easy, I can do that just fine. But even the absolute simplest Device imaginable, that didn't need any input and just maintained a single spell indefinitely, would need to be attached to a mage to do anything - we can't wield ourselves unless we're complex enough to be autonomous. If I made a magical tool, like you're talking about, it would have to be something that wasn't a Device. And I don't know how it would interface because the only interface I already know how to build is Device functions, which you need my kind of magic to use. But, I dunno... I could cast a spell on something that'd persist, if it was the right kind of spell and the right kind of thing. I could probably make a picture crystal if I already knew what picture I wanted to put on it - it might not work exactly like a picture crystal, and it might be tricky to figure out how, but I could. What I don't know how to do is make a picture crystal you could take a picture with. Triggering functions based on, like - physical state changes. No idea."
"Then there's something like this," he deploys the little mana fountain he showed Leekath earlier, "which is a pointless waste of a tiny amount of mana, all it does is make little mana bubbles that jump up and then fade out. It has the diagram to kind of... help define the space. Spell diagrams like that are useful for a handful of things - if there's a spell that's going to be producing visible mana continuously, or if you need to define a flat surface with mana for a spot-shield or floor or something, or if you need to define a location like I did with the Read spell to target those specific books. Probably some other stuff I'm forgetting right this second. But in general a diagram's almost like a - mana proxy? Like, instead of going and physically picking up a book to magically read it, I put a spell diagram under it and do it that way. Or instead of - " he dismisses the mana fountain with its diagram and starts another one from the palm of his hand, "just doing this, I make a spell diagram that does it for me." He closes his hand and cuts off the fountain. "Is that the kind of thing you wanted to know?"
"Incantations, for most of them. An incantation is just - a name, a way of specifying which spell you're casting, out of all the ones you've got. Except long-form incantations also help define some spell structure and targeting. I don't have any spells that cast long-form, though, and I can't think of one offhand that would need to, so I don't have a good example. But a long-form incantation is a full sentence instead of a short phrase, and they're a little looser than short-form, you can change words or phrasings and still be casting basically the same spell but for a different effect. I think they go best with big area-effect spells and complicated matter manipulation. If I wanted to, I dunno, do some kind of complicated sorting on this whole library that filed all the books in the right spot on their shelves, I'd probably be better off making a new spell with a long-form incantation than trying to use the Category Sort I just invented. And the incantation might mention stuff like that I was sorting books into their places on shelves. Or if I wanted to make it snow on the whole school, I might make a spell with a long-form incantation for snowing on large areas. And the incantation would be a sentence about snow."
"You don't," he says, shrugging. "Two different people can invent two different spells with the same incantation. I guess it'd be a compatibility issue if they each loaded theirs onto the same Device... hmm, do I have a contingency for that? Yes I do, I get to rename one or both spells. There you go."
"Yeah! Wow, do wizards have to choose unique incantations? What happens if there's a collision?"
"Spell doesn't work, the invention doesn't stick and you have to pick something else. So old spells, and any spell people want to be easy to remember by referring to old spells as opposed to being easy to remember in some other way, are in gibberish or dead languages, and new spells get long descriptive names or short unique gibberish. For a while it was in fashion to just incant all your spells with your own name - plus whatever you have to add to make sure you don't share it with any other inventors - and then a number for which spell it is, but people kept botching those, they'd confuse the spell number with the power pull or two spells by the same inventor with each other."
"Yeah, that sounds weird and inconvenient, I'm glad my magic indexes per caster. - What happens if you make a new spell the same as an old spell with a new name? Does that work?"
"If it's the same in every respect it'll work just fine. If you changed something - there are some series of spells that have the same incantation but different power pulls for variant effects, like teleporting with assorted numbers of passengers is all the same wording but different power pull and intention."
"Huh. Weird. If I wanted to teleport with a passenger I'd just - include them, but teleportation isn't even an incanted spell for me."
"Yeah. The ones I do come in one shape and it's the shape you saw, but even the other shapes diagrams could possibly be are all flat shapes. The details of that one shape are kind of - attached to me and the way I do magic, a little bit like how mana colours are attached to casters and incantations are attached to spells. I could probably figure out how to cast spells with a differently shaped diagram, or change the shape of mine, but it's basically cosmetic and I like the look of mine just fine so I don't care enough to try."