This blog post describes how to display HDInsight cluster information when a user logs in via SSH.
Linux HDInsight clusters run Ubuntu, which allows you to customise the Message of the Day (MOTD) by placing scripts under /etc/update-motd.d and make the file executable.
The script has been published to GitHub https://github.com/vijayjt/AzureHDInsight/blob/master/script-actions/get-cluster-info.sh