The phrase "to tell the customer" means to provide information or communicate something to the person who is buying a product or service. Full definition
You can't tell a customer what form to select or provide legal advice of any kind. (smartlegalforms.co)
Many companies do not have to warn or even tell their customers about what may be lurking in their products, making it highly dangerous to neglect doing your own research. (simplepurebeauty.com)
You're not telling your customers what they really want and need to hear, and your failure is out there for all to see — on your website, social media and emails. (entrepreneur.com)