Problem

Where are JIRA Workflow Step Descriptions stored?

Resolution

It is stored under language pack jira-lang-en_UK-[JIRA-version].jar located at atlassian-jira/WEB-INF/lib in your Installation directory.

If you unzip the jar file and then navigate to JiraWebActionSupport_en_UK.properties located under com/atlassian/jira/web/action then you would find a tag

# system-issueoperations-plugin.xml

You would find all tool tips under this heading.