Calls and Chats At the same time

When an agent is skilled for both calls and chats if they are on a call and a chat comes in they are offered the chat as well and visa versa. If an agent is on a call or chat how do we prevent another channel from being offered to the agent while they are working with a customer already without having to constantly go in and re-skill the agent?

This would be through the configuration of your omnichannel routing setting explained here.