There is an assumption that well-informed market participants would enable, if not assure, an improved functioning of the markets, and a central bank is in the best position to provide such useful information. However, whether providing information would result in shaping and managing expectations, and if so, whether it is desirable, are difficult issues.
For example, The US Federal Reserve, since 1994, appears to have been providing forward guidance, while the European Central Bank appears to be in the mould of keeping the markets informed rather than guiding it.