Protagonist is waking up from sleep or being unconscious
This is a set up that agents see a lot of in their query box, and the worry is that if we start at the beginning of the day, when they’re just waking up, that perhaps we’re going to see literally every moment of this character’s day – instead of the scenes that are necessary to further the plot.
In the first novel I wrote, I was guilty not of this particular opening, but I was guilty of showing each and every step the character took in a day. Like, they walked to the door, they put the key in, they climbed the stairs… when really, all I needed them to do in that scene was be in their apartment.
Dialogue used as an info dump
e.g., “Well you know that I am your mother and you’re late for the soccer match like you always are.”
Dialogue that sounds unnatural is such a difficult thing to fix as an editorial agent, because you’re trying to teach an author to listen and recognize how people talk in real life, but also to only show what’s necessary to further the plot/scene as well (e.g., deleting all those hellos and goodbyes, etc.) But it would be difficult for an agent to go through a manuscript and finesse every line of dialogue on a submission, and dialogue used as an info dump is usually a flag that there’s either dialogue, world- or character-building issues.
Protagonist breaks the fourth wall to tell you the set up
A lot of times the problem with this sort of opener (e.g. “My name is Barry Mix and I have just the worst luck. You wouldn’t believe it!”) is that it’s incredibly hard to sustain this through an entire novel, and so at some point the novel’s voice starts to shift and feel uneven.
As a writer, I’ve definitely had characters “talk” to me like this – where they tell me their story or what they’re thinking/feeling – as an impetus for a novel. But that doesn’t necessarily mean that their voice when talking to others (like you, the writer) is the best voice for the novel as a whole.
Starting a MG or YA novel from an adult’s perspective
Where a character shows up and how much time we spend with them tells the reader an awful lot about that character’s importance in the book. So when a middle grade or young adult novel starts with an adult perspective, we’re primed to believe that this is the adult’s story. But it can’t be in an mg or ya – and so we wonder where our protagonist went, how long it will take until we meet the real protagonist, and how much of this book is going to be from an adult perspective (with a few exceptions, e.g. Sadie by Courtney Summers, 95 times out of 100 the answer to this last part should be “zero”).
Extensive scenery descriptions with no character
Similarly, long passages of scenery and description at the opening of the novel leave a reader confused about who is most important. We look through the description to figure out where our protagonist is, which makes it hard to really absorb the details – and also difficult to figure out what details are important, since we don’t yet know who is telling this story and why they’re looking at those things in particular. Description works best when we really feel like we’re seeing things through the character’s eyes (regardless of first or third person perspective). What one character does (or doesn’t) notice tells us an awful lot about them.
If you’re not seeing requests on the first five pages of your novel, take a look at the craft issues above and see if a revision would help!