Regardless of the location at which the toolbar is provided (T176422), we want to customise the tools provided by the toolbar in Content Translation. Showing the most relevant tools for this context helps keeping users focused (and contributes to the layout reorganisation proposed in T186873). For example, in Content Translation, a h2 heading is created by translating an h2 heading in the source text, making the menu to select such style less useful in this context.
The capabilities for customisation of the VE toolbar can be used to show only these elements: undo and redo actions, font style menu, link, list menu, and a "..." more menu that provides access to the insert menu. This is illustrated below: