Add a Tooltip in a Web Portal form

It looks like it's implemented in the  CDR-editor:

projects\qbm\src\lib\cdr\cdr-editor\cdr-editor.component.ts

/**
* Gets the description of the cdr.
* That can be the hint provided in the CDRs creation or the description of the column.
*/
public get description() {
// Preferably use CDR-level hint; if none is defined: use the metadata description field.
return this.cdr?.hint || this.cdr?.column.GetMetadata().GetDescription();
}

(method) IEntityColumn.GetDisplayValue(): string
Returns a user-friendly display string for the current data value.

Tried it out:

projects\qer\src\lib\identities\identity-sidesheet\identity-sidesheet.component.ts
console.log(this.data.selectedIdentity.GetEntity().GetColumn('FirstName').GetMetadata().GetDescription())

This returns: undefined

I created an issue for this on the github repository:
Metadata 'Description' fields missing from entityschema endpoint

Please see the github issue linked above for a resolution.