I feel like this is a test to see if you're capable of dealing with dumb instructions.

Disagree. There's a difference to it being understandable vs extrapolating it out from the inputs and outputs. Which is how I ended up doing it.
I think the wording could definitely be improved e.g.
"threshold (threshold) in percentage beyond which the evaporator is no longer useful." Percentage of what? Remaining content or percentage lost?

10662 people passed the kata so I suppose it is understandable. Maybe this post would have been acceptable when the kata was still in beta...
You have examples of inputs and outputs in "Run sample tests".

Sort of a strange way to store your names, but I guess it's all about knowing how to get neccesarry info out of it ^^

Instructions for this kata are very poorly provided. There's no input and output example whatsoever. As a person who doesn't know much about evaporators, I struggled a lot with understanding what I actually need to to.