square.onMerchantCustomAttributeDefinitionVisibleDeleted subscribes to merchant.custom_attribute_definition.visible.deleted for the selected seller. It requires MERCHANT_PROFILE_READ.
Example
automations/square-on-merchant-custom-attribute-definition-visible-deleted.automation.ts
Event
A custom attribute definition that’s visible to your application was deleted. The signal resolves to the officialSquare.MerchantCustomAttributeDefinitionVisibleDeletedEvent payload with type narrowed to merchant.custom_attribute_definition.visible.deleted.