"better" needs to be defined by you.

ucd-snmp became net-snmp a year or two ago.

Version 4.2.4 is pretty stable and solid, 5.0.6 is seeming
so as well, but with several advances.

Both are extensions of the CMU-SNMP whose development stopped
in the early 90's (and annoyingly which picked up several
years later without taking in the improvments that Wes Hardaker
and the UC/Davis team had added.  When left UCD and the project
was renamed "net-snmp" to indicate that.

"I just need a small tool" doesn't really help anyone
make a recomendation for you.  "I just need a computer
to do a little work" might be an analogous request
from a relative.

A first pass might be to at least "make extract" the two
of them and read up on the docs.

 http://www.NetSNMP.org would offer a plethora of information.

Quoting Nicolas Saurbier (Nicolas.Saurbier@biodata.de):
> just playing around a bit with snmp. Now I found two Packages in the PackageSource
> wich deal with snmp. ucd-snmp-4.2.4 and net-snmp-5.0.6.
> 
> Which one is the better one? I just need a small tool, nothing huge.