Not sure about godot 3, but you've tagged as godot 4 anyways, so looking at the docs:
https://docs.godotengine.org/en/latest/classes/class_object.html#class-object-method-get-property-list
the example included there:
@tool
extends Node2D
@export var holding_hammer = false:
set(value):
holding_hammer = value
notify_property_list_changed()
var hammer_type = 0
func _get_property_list():
# By default, `hammer_type` is not visible in the editor.
var property_usage = PROPERTY_USAGE_NO_EDITOR
if holding_hammer:
property_usage = PROPERTY_USAGE_DEFAULT
var properties = []
properties.append({
"name": "hammer_type",
"type": TYPE_INT,
"usage": property_usage, # See above assignment.
"hint": PROPERTY_HINT_ENUM,
"hint_string": "Wooden,Iron,Golden,Enchanted"
})
return properties
Shows that "hint_string": "string of text here"
could be used.