Never really understood talent agents

This has always felt sort of mysterious to me - what agents for actors and comedians actually do on a day to day basis.   

I'm talking about this because of this news:

The Junkyard, managers of Australian comedians like Aaron Chen and Sam Campbell, goes into administration

 Let it be known that, of the younger Australian comedy set, I've always enjoyed Aaron Chen's comedy persona.   That Sam Campbell - well I first saw him recently on an episode of Would I Lie to You (english version) and it was a few years old, but he seemed amusing in a similar eccentric persona to Chen.   But then I think I watched some other clip of him on Youtube and didn't like it, so I dunno.

Anyway, back to the point:   about the only fictional portrayal of a talent agent I can remember is from that Matt Berry series - Toast of London.  And it fitted in with what is probably a widely shared assumption that actor's agents sit around doing nothing much all day other than reading the occasional casting call news and ringing up people on their list and saying "why don't you try this, I think it suits you".   It seems like such a flaky way to make a living - even if, in the case of top Hollywood agencies, it's a very lucrative one.  

But is it really like that?   Does no one do a realistic portrayal of this line of work because it's hard to make "networking" interesting?

Update:   Maybe there was an agent or two featured to a little extent in Bill Hader's dramedy Barry. But I think that shows attack was more against the incredible flakiness of cable television executives.  In fact, I found it kind of amazing that the executives at (I think) HBO let such a damning portrayal of their job be part of the story!  I presume they thought - it's not our network's execs he's attacking - it's the one down the road.