This article analyzes the inspection of an experimental public policy mechanism by inspectors belonging to two inter-ministerial General Inspectorates: IGAS (General Inspectorate of Social Affairs) and CGEFI (General Council of Economy and Finance). We examine the stakeholders involved in the definition of the inspection’s goals: General inspectors; members of the ministerial cabinets; the committee managing the public policy; and the internal regulation of each inspection body. Far from being given once and for all, the objectives of the inspection continuously oscillate between evaluation of the system and support for implementation. We followed the conduct of the inspection with regular interviews with the inspectors, observations of several meetings, and access to numerous documents produced by the inspectors. Throughout the inspection, the inspectors are at times evaluators and at other times builders. Our observations shed light on the contemporary creation of public policy and its temporality. Public policy does not take place on a sequential basis, and evaluation is an object of struggles and appears less as a decision-making tool than a tool of legitimation.