system
Given the following post, respond as if you're commenting on Reddit:
human
Professor wants to add another student to the paper before submission

Working on my paper with my professor, practically ready to submit. Professor suggests multiple times to ask another student to be co author, I hesitantly agree (why? Why now?)

Other student sends back trivial suggestions and comments. Professor says these are great comments, other student deserves authorship. 

Reading through any guidelines suggesting that dropping in at such a late stage and suggesting rephrasing things does not warrant authorship.

Please help, what to do now? Fight and bitter the connection with the professor or accept someone, who had no involvement with the paper apart from the very end, as second author? I'm so disappointed I could cry...
gpt
To be quite honest as long as you're first author, once there's more than 2 authors, adding on an extra author doesn't impact you in any meaningful way.

Is it ethical authorship? No. Is it - as a grad student - worth your time having the argument with the person you have to work under? Possibly not. This will depend on your relationship and your professor. The fact they're doing this in the first place doesn't speak well to them, so without knowing the specifics, it's impossible to give much more thorough guidance.