Advertising copywriter here, I can offer some copy suggestions if you like. Please don't take them as crit of your skill. I love working on descriptions and pitches tho, so here goes.
Summaries are always stronger when there are fewer words doing more work. We want to intro someone compelling, then share the situation (briefly) and establish the stakes. I think you've done a good job hitting these, but we can tighten it up.
Here are some notes on the first parts:
"It was supposed to be just a robbery. Sean Parker didn’t expect to join a crime syndicate."
-Use his full name for impact? Just "Sean" sounds a bit undramatic
-instead of "become part of" just say "join" (less words = more snappy)
I've made an example of this if it were less wordy. I'm not saying my copy is better here, just showing how it can be tightened up. I made some notes on what changed below
Sean Parker's life fell apart when he was wrongfully convicted of robbery. Now, after two years in jail, he's struggling to find a job that will hire an ex-convict. Drunk and desperate, Sean commits the very crime he was sentenced for. When his simple robbery fails turns deadly, Sean is forced to....
-the conviction is presumed and doesn't need to be addressed
-putting in robbery instead of crime is more interesting - it's petty crime, now we have more info about Sean right away -i'd even put in what he robbed: robbing a bank? a convenience store?
- You have some grammar errors in your text, so maybe pop it in Grammarly or get a second eye on it? (Eg. the expression is "on the cusp" )
-"However" isn't a compelling term, and softens the following sentence.
- I don't know what acting as a dead man means, could you rephrase that?
-you can combine the foodchain thought with killing the king since it's reiterating the same info
Ok that's some info...and I dunno if you even want it. so I'll stop here. hope it helped!