Steps to reproduce (assumes ChromeVox or similar)

1. Open https://elastic.github.io/eui/#/display/tooltip in a new tab.
2. Tab to any tooltip-enabled element, such as the first link "top" in the page content

Actual Result

The link text is read but not the tooltip

Expected Result

Link and tooltip are read

Category: #750: Elastic UI Tooltip Accessibility
Relevant WCAG Criteria: 1.3.1 Info and Relationships