1. A method for optimizing a metrology tool for measuring one or more characteristics of a semiconductor target, comprising: (a) providing a set of specifications and an initial input data for a particular target, wherein the specifications provide limits for characteristics of images that are to be measured by the metrology tool including a TIS (tool induced shift) value limit; and (b) automatically optimizing one or more settings of the metrology tool for measuring the particular target so as to meet one or more of the provided specifications without further significant human intervention with respect to the metrology tool, wherein automatically optimizing one or more settings of the metrology tool includes adjusting a dual aperture device (DAD) position so as to meet the TIS value limit or a single-grab and double-grab (SG/DG) setting so as to meet the TIS value limit.