Could be, unless both narrator and characters participate in dialogue. Why the narrator? Because despite substantial overlap in first person point of view, the narrator’s always a step ahead of the character. As storyteller, the narrator already knows the ending, and describes the trouble, rather than enduring it. Finally, the compassionate, insightful, charming, witty narrator can accomplish many things that characters can’t. Like speed up dialogue.
In rare instances, the tension soars and the dialogue is pitch-perfect. Then the narrator summarizing or describing would damage that white-hot pacing. Usually, though, you achieve optimal grounding, momentum, and insight when the narrator and characters create the illusion of conversation, which isn't much like an actual conversation. In this example from Saturday, Baxter and his accomplice Nigel hold an entire family hostage, including pregnant young Daisy:
Baxter puts his right hand in his pocket again. “All right, all right,” he says querulously. “I’ll kill you first.” Then he brings his gaze back onto Daisy and repeats in exactly the same tone as before, “So, what’s your name then?”
She steps clear of her mother and tells him. Theo unfolds his arms. Nigel stirs and moves a little closer to him. Daisy is staring right at Baxter, but her look is terrified, her voice is breathless and her chest rises and falls rapidly.
“Daisy?” The name sounds improbable on Baxter’s lips, a foolish, vulnerable nursery name. “And what’s that short for?”
“Little Miss Nothing.” Baxter is moving behind the sofa on which Grammaticus is lying, and beside which Rosalind stands.
Daisy says, “If you leave now and never come back I give you my word we won’t phone the police. You can take anything you want. Please, please go.”
Even before she’s finished, Baxter and Nigel are laughing. -- Ian McEwan, Saturday
What if each character talked constantly instead of the narrator paraphrasing? What if you cut what the narrator adds to this passage? No, the narrator and characters must hold their own dialogue, with the narrator speeding, hinting, developing.
At the opening of Alice Hoffman’s Here on Earth, the mother and daughter have a brief exchange about being in a strange place, mired in the mud in an unpredictable car:
“We’re going to get stuck,” March’s daughter, Gwen, announces. Always the voice of doom.
“No, we won’t,” March insists.
Three paragraphs of narrator summary bring readers to the climax, omitting the obvious or redundant.
“We’ll get out of here,” she tells her daughter. “Have no fear.” But when she turns the key the engine grunts, then dies.
“I told you,” Gwen mutters under her breath.