agree with this, after introduction the role becomes parasitical, unless that agent has an agreement with you directly to constantly find other / better opportunities on your behalf. Given what I know about employment law, they should not be able to do this if they also represent the end employer.

another way to look at it is to review your ideas on rent seeking as being 'always bad'. I think in most cases it is, but perhaps we can also understand rent seeking as a pen test of a system, forcing it to improve. Parasites exist in biology - the trick maybe to try find a way to make them symbiotic rather than just parasitical

good luck!