A custom field on an account is used to track finance information about a customer.

Create a permission set that allows read-only access to the field via Field Level Security and assign it to the agent.

Create a new profile to allow for read-only access to the field via Field Level Security and assign it to the agent

Update the Customer Service Profile already assigned to the agent to allow for read-only access to the field via Field Level Security

Update the custom field’s Field Level Security in setup to allow the agent read-only access to the field.