I read it mid 80's and found it a few years ago, but with the publication of a new Jewish sci-fi novel, it's harder to find it again.
The story is about an investigator working for a government agency regulating technology or some such.
He has a bag of tricks and complains towards the end that the antagonist has something better.
He also had an alien monkey sidekick IIRC. Something of an ace in the hole.
Lots of Jewish, Yiddish phrases including Sitra Achra. It's a funny novel, filled with jokes and humor.