- Updated `EuiToolTip` with a new `setAriaDescribedBy` prop. This defaults to true (reflecting prior behavior), and can now be configured to `false` if your tooltip contains duplicative content or (e.g. when setting your own `aria-label` or `aria-describedby` attributes).

**Bug fixes**

- Fixed `EuiToolTip` overriding instead of merging its `aria-describedby` tooltip ID with any existing `aria-describedby`s