Tool of the Trade by Joe Haldeman
My rating: 3 of 5 stars
"Tool of the Trade" belongs to a sub-genre of SF that could be called "Simon Says".
What if someone had the power to make other people do what they wanted, if free will came with an asterisk? This is entertaining source material that's mined over and over again in comic books (here are two examples: 1 2).
For the story to work, there have to be limitations on the power, a class of people who are immune, or some other reason why life isn't infinitely easy for someone who can just order people to do what they want. This story is no different. It plays with the material, but only goes so far in exploring the limits.
Haldeman's take on this sub-genre interesting is notable for its Cold War setting, its spy-novel flair, and its ending (which I won't spoil). It's also yet another example of Haldeman's enduring skill as a writer, which lies in taking a slice or two of SF and applying it on a human scale, with both drama and humor mixed in. Even when his subject is the nature of the universe itself (as in "Forever Free"), he still fills his characters with desires, with intelligence, with a sense of humor.