That looks more or less standard as far as it goes. There are some variations on where the converter is connected, but what you have is reasonable and the wire sizes look appropriate to me.
Typically the vehicle battery and the house battery are connected together by some sort of an isolator device, often completely separately from the other wiring. There are a few different isolator devices used, but the intention in every case is to only join the two electrical systems together when the engine is running and to keep them separate when the engine is shut off so that running the house battery down doesn't discharge the chassis battery.
One not uncommon and rather straightforward system is to have a high-current continuous duty solenoid to connect the two systems together, and power the coil from a circuit switched by the "run" position of the ignition switch. (Sometimes a little more complex control arrangement is used, either with a time delay or a chassis battery voltage monitor added in to ensure the chassis battery charges before the house battery, or to permit the chassis battery to be charged from the converter when appropriate, or whatever.) Often there is also a momentary switch to turn on the solenoid as an "emergency start" switch in case you happen to leave the headlights on or something, a sort of built-in jumper cables.
There are also diode-based isolators available that don't use a mechanical solenoid. There are probably some other systems in use, too, maybe based around a solid-state relay (likely a power FET under the covers), but the basic concepts are similar.
On my motorhome, the isolation relay happens to be mounted near the house battery, and connects to the chassis electrical system with what I think is a 2 guage wire. There are large (I think 175A) fuses on either end to protect against shorts. The self-resetting circuit breaker for the house distribution panel connects between the big fuse and the isolation relay, as do a few other miscellaneous things (the wire for the generator starter, the electric steps via an appropriate fuse, and one low power lead that goes off somewhere...maybe the radio preset memory, I'm not sure.) Between the battery/self-resetting circuit breaker and the house distribution panel is the house disconnect relay, a latching relay that connects to what's commonly called the "salesman's switch."
On my particular motorhome, the converter also connects more or less directly to the battery, through a circuit breaker, rather than the distribution panel, but I think that's based mainly on how things ended up being mounted and positioned. It does mean that the converter will charge the battery even if the disconnect switch is off, which is a bit atypical.