Diagnostic Clinical Genome and Exome Sequencing

In “Diagnostic Clinical Genome and Exome Sequencing”, Biesecker et al. are critical of the way doctors have been ordering CGES tests in the past and offer new factors for a doctor to consider before ordering the CGES test. They define the basics of CGES testing and suggest various measures that should be taken prior to placing an order for CGES.
Why should a doctor compile an extensive history/profile Of a patient before ordering CGES? What should be included and why? How will this information be beneficial in terms of narrowing down sequencing options?