Look at the Table of Contents; is it detailed or vague? Does it follow a logical track?
Look at the Index; is it extensive enough to be useful? Most library catalogs tell whether there is an index.
Does the work have a bibliography? Is it comprehensive or just a selected list?
Does the author cite sources within the text to provide evidence? Most library catalogs tell if there is bibliography or reference list.
How reliable and authoritative are these sources?
If the argument relies on data, who collected and analyzed it? How old is the data?