Source

File: wp-includes/rest-api/endpoints/class-wp-rest-controller.php

public function get_public_item_schema() {

		$schema = $this->get_item_schema();

		if ( ! empty( $schema['properties'] ) ) {
			foreach ( $schema['properties'] as &$property ) {
				unset( $property['arg_options'] );
			}
		}

		return $schema;
	}