Yeah, when pax have lost bags or need to recheck their bags, they should just let them fend for themselves. /sarcasm

Agents have ways been in the customs area and for good reason. They have to be there for CS/baggage issues, maintenance issues (I,e, with the baggage system), connection help (I.e. a missed connection or prioritizing lines at busy times), handling deportations, etc. Agents allowed access to the “customs area”, officially the FIS have to go through additional screening (more so than the average airline employee). They’re only allowed inside if they have business in there. Most airports use a small customs seal somewhere on the badge as the denotation for if an badge holder has access to the FIS. And of course they can’t access the doors to the FIS areas if their badge isn’t so enabled. Violating any of the customs rules can get one in some serious doodie.

source: I used to manage a customs areas at IAD in a past life, also had customs access at ORD when I worked at UA’s HQ nearby (for some capital projects I was working on).