Add Tooltips to a dynamic field within a Dashboard

Hello Looker Community!
I want to add a tooltip to my dashboard (which is really a merged query) to display a description. I understand you are supposed to do this in the view file but the fields I am trying to do this to are dynamic fields so this method cannot be done. I have tried adding a description to the dynamic field, but I find it does not show up on the dashboard.

The code for the dynamic field is below. I would really appreciate if someone knew how to get description to be displayed as a tooltip and why looker could be ignoring this description I added here. Thanks in advance!

dynamic_fields:

  • category: measure
    label: New Customers
    based_on: view_name.count_distinct
    _kind_hint: measure
    measure: new_customers
    type: count_distinct
    _type_hint: number
    filters:
    view_name.field_name: ‘Yes’
    description: “Description!”
    show_view_names: false
    defaults_version: 1
    join_fields:

You can try to customize your ToolTip using the LookML html parameter,
Here’s the link:
https://cloud.google.com/looker/docs/best-practices/cookbook-visualizations-tooltip-customization