Can you share a minimal, reproducible example (MRE)? A complete script that can be copied/pasted and immediately run, as-is, with no modifications. This is much more useful than snippets.
In the absence of a specific example, we can only guess.
Here is a bit of code that shows how to set up a custom hover output
from bokeh.models import HoverTool
# Syntax: $. are 'special fields': $x inserts the x-coordinate
# @. are fields from the color data source:
# provide an extra column of values and declare it's name as a vdim (or sue a pd.DataFrame)
data = pd.DataFrame( { 'x': [1.1, 3.2, 5.8 ], 'state': ['NY', 'NJ', 'PA'], 'stuff': ['a','b','c']} )
hover = HoverTool(tooltips=[("error", "$x"),
("state", "@state"),
("stuff", "@stuff")
])
hv.Scatter( data, kdims='x', vdims=['state', 'stuff']).opts(tools=[hover], size=10).redim.range(x=(0,7))