Calvin Coolidge, purposely pulling back on the reins of government actually requires more effort than is typically expended by a more activist leader. During his five years in office, President Coolidge certainly found it so.
For all of its considerable detail, I did find Shlaes' narrative to be lacking in certain areas and inartfully crafted in others. Coolidge's money-saving economic policies get most of the attention, as they should, but there is little on Coolidge Administration foreign policy save for the last-minute drive to ratify the war-"outlawing" Kellogg-Briand Pact. The U.S. was not "isolationist" during the 1920s in any meaningful sense of the word, but Shlaes inadvertently leaves that impression. As to Shlaes' style, it is best described as "lumpy." Characters are repeatedly reintroduced to us, while other figures who might have been expected to get much more attention, such as Coolidge's secretary C. Bascom Slemp, barely rate a mention. The short-shrifting of Slemp (whom blacks, who at the time were still heavily Republican, harshly criticized) seems particularly unfortunate because he was a Virginia Republican at a time when Southern Republicans were rare; including him as a major player would have added some depth to the comparatively scanty discussion of Coolidge's policies towards the South and black civil rights.
If you are interested in learning about Coolidge's life, personality, and Presidency, this is a fairly decent introductory book, but I still came away somewhat disappointed. Several more runs through the editorial mill would, I believe, have strengthened both the content and the prose.