How to check a book's content warnings and mood before you read
Reader-tagged sites such as StoryGraph and Hardcover list a book's moods and content warnings; publisher pages and the author's own website sometimes list them too. Check them before you start, especially for themes you avoid, and use spoiler-free summaries rather than reviews if you don't want plot details.
Where content warnings live
Community sites tag books with content warnings and moods contributed by readers. Many authors now publish warnings on their websites or at the front of the book. Searching the title with "content warnings" usually finds a spoiler-free list.
Checking a book for a younger reader
Age labels from publishers are broad. Look at what specifically appears — violence, sexual content, strong language, self-harm — and judge against the reader you have in mind rather than a printed age band.
Getting it in one place
When Hunch evaluates a book it includes its moods, content warnings and a factual age advisory alongside your personal score, so you can see both whether you'll enjoy it and what is in it before you start.