Hi, John,
There is a package called ggplotly that convert ggplot to plotly object by providing tooltip and other attributes as required.
Syntax:
ggplotly(p = ggplot2_object, width = NULL, height = NULL, tooltip = "all", dynamicTicks = FALSE, layerData = 1, originalData = TRUE, source = "A", ...)
Ex:
ggplotly(ggplot_object, tooltip = c("text", "size"))
Hope it helps!