The pattern argument (a regular expression) will filter the list based on the info argument, which defaults to "name". Use the info argument to specify another info type, or a string of several comma-separated types. Info types depend on the target systems, as well as the Simics Agents, but will at least include: agent, capabilities, hostname, machine, name, release, system.
A Simics Agent is declared dead and removed from the list, if it fails to make contact within a timeout period after the end of the agent poll interval. This timeout is defined per Simics Agent and can be controlled via the stale_timeout attribute on any of the connected agent handles. When an agent is declared dead, its handles will become stale and their commands will be canceled. New commands cannot be given to a stale handle.
With the -verbose flag, some additional information is included.