Add tags to a contact
Add one or more tags to a contact identified by phone number. Use this tool to organize contacts by assigning tags for segmentation and targeting. Tags must exist in the system before being added - use GET /tags to retrieve valid tag IDs. Provide either tag_ids (recommended) or tag names. Set create_missing_contact=true to automatically create the contact if they don't exist in your Dripcel account. Response includes matchedCount (contacts found) and modifiedCount (contacts updated).