A countercyclical fiscal policy tool is a government strategy used to stabilize the economy by adjusting spending and taxation in response to economic fluctuations. When the economy is experiencing a downturn, the government may increase spending or cut taxes to stimulate demand, while in times of economic growth, it might reduce spending or raise taxes to prevent overheating. This approach is critical in managing price stability and inflation, as it aims to counteract cyclical trends in economic activity.