En wants a quiet life working on mechanical marvels. The invaders want her to work on their lethal dehydration guns instead. Nice! Good hook. I'm invested.

The known world is a sunken basin, and the sides of that basin are impenetrable clay, referred to as “the Wall”. Mechanic En Etspring’s small desert hometown is nestled safely into the edge of the Wall. Like they are suspeneded there? Might be a little too much description here. What you are saying is that basically they are isolated, which is covered without the added detail of "nestled into the edge of the wall." But this safety proves to be an illusion when a hostile army arrives, and En must cooperate with them to keep her family safe. Townspeople begin to go missing, including En’s love interest Mo, a blacksmith. At the same time, an ambitious and ruthless invader named Javier has begun to take a dangerous interest in En. Soon, the only way to protect herself and her family is to flee her hometown into the lukewarm embrace of a group of rebels. Is it a surprise that these rebels exist? The "known world" felt small by the earlier description. Was her hometown the only known habitation? Why is the embrace lukewarm? Now that En is free, she is ready to be done with making weapons, but the rebels want her to share her new expertise. For En, escaping town isn’t the same thing as escaping the consequences of her decisions - or the jilted Javier’s revenge. So now she is being asked to make weapons again, but to use against the invaders this time? Feels a little anticlimactic. Maybe some inclination of if she feels any difference about who is on the other end of her weapon? Or is she a pacificist through and through?

Firebelly is an 86,000 word science-fiction adventure story about a young woman balancing conscience and survival, set in an alternative world. It will be my debut novel. Hopefully it is the first of many to include fantasy-style names and dragon motifs. No need to clarify first novel, that can be assumed. I would strike the last sentence as somewhat confusing - you're not clarifying whether this is series potential or themed career potential, and also the dragon motif might fit the title, but not the novel description./span>

Right now I like what you have, but I feel like there needs to be a little ray of hope or an alternative choice for En. Make weapons or... make weapons, doesn't feel like a plot. Is she searching for an alternative? Questioning pros and cons of using her skills against invaders? We know there's a moral quagmire here, but how is it playing out through her actions in the plot?