create_contacts include the country code. A duplicate number does not create a second contact.
Contacts
Labels
list_labels, get_label, create_labels, update_label, and delete_label.
Deleting a label removes it from contacts. It does not delete the contacts. create_labels accepts up to 50 labels, each with a name of at most 120 characters. update_label changes one label.
Attributes
list_attributes, get_attribute, create_attributes, update_attribute, and delete_attribute.
Attributes are the custom fields on a contact. Define the attribute, then set its value on the contact. create_attributes accepts up to 50 attributes. update_attribute changes one attribute.
Phone numbers
list_phone_numbers returns the sending lines on this WhatsApp Business account, including phoneNumberRef.
Use a phoneNumberRef on send and list tools when the account has more than one number. A template still belongs to the WhatsApp Business account. The assistant does not describe a template as sending from one of these numbers.
get_api_key checks the Bearer key and returns timeZone, which scheduling uses when you do not name a zone. See Rules.