Hi ScoutFinch! So happy to have you!
Your excerpt looks cool! Describing anything sci-fi/fantasy is always tricky, and I don’t have much experience with it, but I’ll try to help from what I’ve seen others do.
Your description is good and comprehensive, but maybe you should start a little bit wider. You might have done this earlier when Jade ended up there, but if you haven’t, I’d start with describing the monster very loosely. Comparing it to some animal or mix of animals makes it easier to visualize. (You’ve actually done this already when you mentioned it looked like a lizard.)
And you could possibly filter the description through Jade’s POV a little more, as his emotions change how he describes the monster.
(You can actually completely cut “Jade took a better look at the monster.” Since he’s describing the monster, it’s obvious that he’s taking a better look at it.)
The monster wore pants, but its exposed chest revealed rippling muscles under its scales. Jade shuddered. The monster could snap him in pieces. He felt too small, too fragile.
The hand-like claws were strong but dexterous as they (Whatever action they’re doing to the helmet).
He frowned. An anthropomorph? (Etc.)
This way you can cut a couple of the details while keeping the impression intact. You don’t get too caught up in details, but it’s always tempting. (As said by the person who has the tendency to describe things in excruciating and irrelevant detail to the point of being ridiculous. Maybe I should try taking my own advice for once XD)
The second piece is good too! It raises a lot of interesting questions! There are one or two things you could streamline.
The eyes as they peered down the long muzzle were large and round, the irises chemical blue and circular pupils instead of the gash-like slits its kind had.
This piece in particular. You’re trying to put too much information in one sentence. I can see why you’re describing the eyes in so much detail, (It’s really cool!) and I’d keep that.
Splitting the sentence up could make it a lot clearer:
The large eyes peered down the long muzzle. They were an unnatural, chemical blue. Instead of slit pupils, his looked normal, almost human.
Hope that helped!
"Stories are light. Light is precious in a world so dark." The Tale of Despereaux