This may seem like a bit of a weird question but I’ve seen lots of vocab lists and kanji lists for each level of the JPLT. If something is on the ‘vocab’ list does that mean it’s not necessary to know all the kanji reading for those vocab words on the test?
Or is it that the vocab words are composed of kanji you already will know that are on that level’s kanji list. For example - all N3 level vocab is composed of N3-N5 level kanji that you’ll know already if you are level 3.
Does that make sense? It’s something I’ve been curious about every time I see a vocab list for the JLPT but it’s honestly never been clear to me. For context, I haven’t studied for the JLPT or anything so I genuinely have no clue.
To add to what Leebo said, you will not be asked to produce readings for kanji in isolation - it always happens in the context of a given word. There are some tests online to serve as examples, so you can see what kinds of questions they ask. IIRC you get a word in a sentence that’s written with kanji, and you need to select the correct hiragana writing, and there are also questions where the word in the sentence is written in hiragana, and you need to pick the correct kanji. But it’s not that they show you a kanji without context and ask you to select a reading for it.
Therefore it’s a really good thing to know the vocab well