Build your credibility
Are the methods clear?
Providing a (short) list of sources of information and publications that were drawn upon in the analysis can be helpful. However, giving a detailed description of the methods is neither helpful nor necessary. As one study found: “researchers are preoccupied with controlling for bias, but the [policy makers] aren’t interested in the details, they just want to know what works”. You need to be clear about where your data is from, but you do not need to explain the methods in detail.
Is the policy brief clear about where the evidence was drawn from? Is it from a single study or a synthesis of studies?
Have you established your credibility?
Policy makers pay attention to who produces a policy brief. Establishing the credibility of your organisation over a long period is much more important than a specific piece of research.