These are some extra options available for broker settings:

maximum execution time - after that if the agent was not released will be considered as timed-out and will be reused (you should adjust this to your needs, you can increase this to allow your programs to finish execution but this could lead to no agent being available)
communication time-out - used in broker-agent communication
message packet size - this is the size of packet in kilobytes used by agents when sending the result back to the requesting client (a greater value is much faster but will need more memory for running agents)
agents filtering options - this could be DENY or ALLOW, if you don't specify a custom file the default will be used ([broker name].host)