If you underpunctuate your draft, readers might misinterpret the meaning.

The manuscript was rejected because it was underpunctuated and difficult to follow, so the author was asked to add punctuation.

The editor underpunctuates the manuscript, leaving readers to guess the intended pauses.

The editor highlighted multiple instances of underpunctuation in the manuscript, noting that missing commas and periods made the meaning unclear.

By underpunctuating her emails, she left colleagues confused about the meeting time.