i wouldnt reword the card, sol. most people should understand the effect of the card as is, just as if a sign on the road were to say "construction ahead, use an alternate route", a person wouldn't think "well, alternate can mean that you go back and forth, so should i go to a different route, go back to my main route, which is closed, and then go back to the different one, and then back to the main one that is closed, etc?"- a normal person would know "oh, alternate has many definitions, but the only definition that truly makes sense in this situation is to pick from the many alternatives". its called reading comprehension.
not every detail can make it on to the card text, nor should they. thats what the notes section is for. yes, this does require some work on the behalf of the reader, not everything can be bundled up in the cliff notes on the card itself.
"Randomly convert some of the opponent's quantums into other elements. " from Discord in game lets you know what you need in order to use the card appropriately. if you want to rage that it doesnt go into the detail of defining "some", thats really an issue with you, not the card. and this isnt "done badly", its called "sufficient".
Christ, grammar and punctuation. Did you just graduate from grade school?
The problem with your example is context. In the context of the road construction, the reader only needs to apply the general definition of the word alternate, and can choose which other route to take for themselves. In elements, which altenate route the effect will take matters greatly,as stragetis will be built around the outcome.
If a user has to leave the game to find out what a card does, it's not clever design. It's obnoxious laziness on the behalf of the developer. If you have trouble fitting the entire description onto the card, cut out some of the padding around the card and make space.
Why shouldn't the entire ability be described in the card text? It adds no value to the game to leave it out, and is just plain laziness. The current discord is not a paragon of useful card text. Instead of using existing cards as an excuse to slack off, fix the existing cards. "Good enough" isn't the mindset a flash game should take, not with the vast array of free alternatives available.