(a) The pension impact note shall be factual in nature, as brief and concise as may be, and shall provide a reliable estimate of the impact of the bill on any public pension systems to be effected by it, in dollars where appropriate, and, in addition, it shall include both the immediate effect and, if determinable or reasonably foreseeable, the long range effect of the measure. If, after careful investigation, it is determined that no dollar estimate is possible, the note shall contain a statement to that effect, setting forth the reasons why no dollar estimate can be given. A brief summary or work sheet of computations used in arriving at pension impact note figures shall be included.
     (b) The pension impact note for any legislation or amendment that the Commission on Government Forecasting and Accountability determines would result in an increase in benefits or increased costs to a pension fund established under Article 3 or 4 of the Illinois Pension Code may demonstrate the fiscal impact of the legislation being considered on selected individual municipalities with such pension funds.