In fiction it seems sometimes better to be clear than subtle. This is maybe the opposite of what you'd expect; there is a strain of thinking that values subtlety. It can be good. It also seems not to be strictly necessary. An example from Soul Music:
The grin appeared to widen.
"I hear you boys are in a bit of trouble," Dibbler said. "Broken furniture and whatnot."
"We're not even going to get paid," said Cliff, glaring at Glod.
"Well now," said Dibbler, "It could just be that I could help you there. I'm a businessman. I do business. I can you see you boys are musicians. You play music. You don't want to worry your heads about money stuff, right? Gets in the way of the creative processes, am I right? How about if you leave that to me?"
"Huh," said Glod, still smarting from the insult to his financial acumen. "And what can you do?"
"Well," said Dibbler, "I can get you paid for tonight, for a start."
"What about the broken furniture?" said Buddy.
"Oh, stuff gets broken here every night," said Dibbler expansively. "Hibiscus was just having you on. I'll square it with him. Confidentially, you want to watch out for people like him." He leaned forward. If his grin had been any wider, the top of his head would have fallen off.
"This city, boys," he said, "is a jungle."
"If he can get us paid, I trust him," said Glod.
"As simple as dat?" said Cliff.
"I trust anyone who gives me money."
Buddy glanced at the table. He didn't know why but he had a feeling that if something was wrong the guitar would do something–play a discord, maybe. But it just purred gently to itself.
"Oh, all right. If it means I get to keep my teef, I'm all for it," said Cliff.
"Okay," said Buddy.
"Great! Great! We can make beautiful music together! At least–you boys can, eh?"
He pulled out a sheet of paper and a pencil. In Dibbler's eyes, the lion roared.
The main characters here (Glod the dwarf, Cliff the troll, and Buddy, the human guitarist and our point of view character) are the band members and C.M.O.T. Dibbler. The band has been playing at Hibiscus's bar, and the crowd's gone wild, but the band has broken some furniture and they aren't going to be paid because of that. Hibiscus is a troll and I think some kind of shady or criminal character. The band has retreated to a room away from their fans in the bar (who, because of the spooky magical guitar, won't stop asking for encores). C.M.O.T. Dibbler is the man who has just walked into the room. C.M.O.T. Dibbler wants to be their manager. If I recall correctly, he's this plot thread's main antagonist.
How do we know he's the antagonist?
There's the subtext of the circumstances, the dialog, and the narration. He's offering to take care of money (implicitly: entirely, as in with no oversight or partnership) so they "don't have to worry" about it. They're in a bad spot with Hibiscus, the bar's owner, and he gives them a minimum acceptable offer: He'll get them out of the bad spot, he'll get them paid for tonight. He tells them the city is a jungle–implicitly: It's dangerous, you need me to protect you. There's the closing line that implies he's the lion in the jungle–implicitly, not the protector but the danger he warned them about. (Forgetting that lions don't actually live in the jungle, because the meme is that they do.)
There's the surface stuff. He smiles too much, too wide. He's a bit too modest: "At least–you boys can, eh?" He's generally a little bit too casual and friendly (or in the wrong ways?) for having just met them.
Finally, the characters themselves are suspicious–suggesting maybe we should be too. Glod is skeptical at first, asking "And what can you do?" Cliff, too, isn't entirely trusting: "As simple as dat?" Buddy's unsure, but clearly suspects Dibbler is a bad dude: When he looks to the guitar he's expecting a discord, not something nice to hear.
So, three supporting lines here: Subtextually shady behavior, surface characteristics, and "our" characters' reactions. These redundantly and densely point in the same direction: This dude is bad. The message is clear; it's not supposed to be clever or subtly implied: Watch out for C.M.O.T. Dibbler. And it works.