Service teams need to have a clear understanding of what government wants to change or achieve through its policies. You should find this information in a statement of policy intent. This will explain what outcome or set of outcomes the policy has been designed to deliver. It may also outline what outcomes should not change.

https://www.gov.uk/service-manual/design/understanding-and-meeting-policy-intent

Service teams are expected to deliver new, existing or changing policy when they are developing a service. Both policymakers and service teams face similar challenges in translating government priorities into policies and services that affect people’s lives.

Policy teams design, develop and propose solutions to help meet ministerial objectives based on research and evidence. They make sure the effective delivery of policy, evaluating its impact and adapting as necessary.

Many government departments are trying to embed user-centred design into policy making. Service teams may have the opportunity to work with policy professionals to design a range of policy options so that ministers can make more informed decisions about which one to follow. Your role may involve highlighting unintended consequences and risks and showing how a particular policy might not work.