He is tough boy vs He is a tough boy

Some examples from the web:

• So I'd turn up at all the house parties where the tough boys hung.
• Okay, we don't need to go down the tough-boy route.
• Your tough boy put you out on the street, Rosie?
• He's a pretty tough little boy, you know?
• Tough luck, boys. I'm trying out my new gun.
• From over on our side, we got the idea he led a mighty tough bunch of boys.
• Maybe we seem a little tough on our boys... but deep down, we love them.
• What's tough is, you boys did more in a night than I could in two years of talking.
• When things got tough with those boys, they didn't run around looking for "isms."
• That man, he is tough as nails.
• Getting dressed is tough, but dressing as a girl with boys clothes...
• It's like he needs to prove he is tough.
• Be warned: I got me a new assistant coach, and he is tough as nails.
• Mr. Tolson, he is tough, isn't he?
• This is tough love, Charlie.
• Destroying high-tech electronics with glorified camping equipment is tough but not impossible.
• Three and a half floors is tough.
• Look, Nathan, she is tough as nails.
• The boss is tough, but fair.
• Knowing what it is is tough.

Some examples from the web:

• So I'd turn up at all the house parties where the tough boys hung.
• Okay, we don't need to go down the tough-boy route.
• Your tough boy put you out on the street, Rosie?
• He's a pretty tough little boy, you know?
• Tough luck, boys. I'm trying out my new gun.
• From over on our side, we got the idea he led a mighty tough bunch of boys.
• Maybe we seem a little tough on our boys... but deep down, we love them.
• Okay, Burke, I have put in a request with the bureau to have Pratt moved out, but until then, he is a private citizen who is leasing an office for his charitable foundation, and booting him out is a tough sell.
• Boy, this is a tough one. I don't know if I'm supposed to be hoping
• Desertion is a tough charge to beat.
• This is a tough conversation for me.
• This is a tough party to get into.
• Consequently, championing democratic values in Belarus is a tough task.
• Listen, this is a tough time for me.
• Kenzi this is a tough time.
• This is a tough time of year for him.
• The human flesh is a tough shell.
• This is a tough deposition for everybody.
• LA is a tough place to be romantic in.
• It is a tough road to home for Saracen.