The message here is good: young men need to "be real" with each other, secrets hurt, etc. But there were major problems in the story that made this message too didactic and narrow-lensed to digest.
Maldonado uses an urban kid-speak dialect that rings false because it is too clean. (Except it does use the word "f*g**t". More on that in the next paragraph.) Here's a problem a lot of ya authors face, so by itself, I wouldn't knock it, trying to find a balance between language that is real and getting libraries and classrooms to put the book on their shelves. But if this book is trying to make a point about honesty it needs to start with the language.
The characters in this book are homophobes, and the author makes no effort to address it. One peripheral character is mentioned as gay, when clearly his actions demonstrate a trans identity, and this confusion is completely unaddressed. I would go so far as to say the attitudes toward homosexuality are hostile and fight against the book's effort to support honesty, respect, male identity and deep friendship.
The author doesn't seem to trust his ability to let his characters learn through experience, and resorts to using "real convicts" that visit a classroom and tv talk shows to preach a message of "Don't hide your problems from people you think you can trust" (p. 188). That is, unless you're gay. You should hide that.
So, spoiler alert, Sean gets weird and violent once he starts visiting his dad in jail (the secret he is keeping from his friends). (Actually, the author uses the word jail, but names the institution, Clinton County Correctional Facility, which is actually a prison. To me, that's significant.) I get that keeping that kind of secret can be damaging. I get that kids may feel embarrassed or less-than to have a parent in jail/prison. But the author contrives for Sean to see the light and change his violent behavior, not because he's now more open with his best friend, but because he stops visiting his dad. I don't claim to be an expert on the psychology of kids with incarcerated parents, but I do know that formerly-incarcerated parents recidivate less if they have strong bonds with their family, and family bonds are maintained over the length of a sentence by regular family visits. This book appears very concerned about urban kids from fatherless households, and yet advocates for breaking bonds between incarcerated fathers and their kids. This book positions kids as easily influenced, impressionable, and simultaneously entirely responsible for their choices, and incarcerated fathers as failed, irredeemable, and possibly gay. This book seems to me to reiterate an old and tired narrative under the guise of being gritty and espousing a new, more sensitive masculinity.