This issue was reported by Fabrice Bacchella in the users mailing lists. Quoting him: ovirt shell uses PAGER for all output, even single line one. I was using PAGER=less, it made it barely usable. That's strange any way for a interactive shell.
The reason for this is that by default the "less" program pauses after the output waiting for a key press from the user, regardless of the length of the output, and the CLI calls the "less" program for outputs with very small number of lines, some times even zero lines. For this reason the default pager command used by the CLI is "less -FXR", where the "-F" option tells "less" to not pause if the output doesn't take all the available screen space. We should modify the CLI so that it uses the pager only for potentially large outputs and not when the number of lines is small (prompts, error messages, etc). Meanwhile, as a workaround, you can set PAGER="less -F", that should help.
There aren't plans to update the CLI, so this won't be fixed.