When a manager adds a team member to their account, they're able to restrict the team member's permissions to certain lists of contacts.
Team members can only send messages to contacts on the lists they have access to. The same applies to inbound messages.
For this reason, we highly recommend account owners grant team members full list permissions. Otherwise, they may miss out on some messages.
You should only restrict list permissions if your team member plans to send campaigns from your primary number to large groups, and you don't want them to accidentally send a message to the wrong list.