Sometimes, to be sure, a side remark adds piquancy and a personal savour.
But the general rule is, great discretion in this respect.

Every epithet or adjective beyond what is needed to give the image, is a
five-barred gate in the path of the eager mind travelling to a climax.

Explanations and moralising are usually sheer clatter. Some few stories
necessarily include a little explanation, and stories of the fable order
may quaintly end with an obvious moral. But here again, the rule is--great
discretion.

It is well to remember that you have one great advantage over the writer
of stories. The writer must present a clear image and make a vivid
impression,--all with words. The teller has face, and voice, and body to
do it with. The teller needs, consequently, but one swiftly incisive verb
to the writer's two; but one expressive adjective to his three. Often,
indeed, a pause and an expressive gesture do the whole thing.

It may be said here that it is a good trick of description to repeat an
epithet or phrase once used, when referring again to the same thing. The
recurrent adjectives of Homer were the device of one who entertained a
childlike audience. His trick is unconscious and instinctive with people
who have a natural gift for children's stories. Of course this matter also
demands common sense in the degree of its use; in moderation it is a most
successful device.

Brevity, close logical sequence, exclusion of foreign matter, unhesitant
speech,--to use these is to tell a story directly.