We describe agents that are customizable information assistants for space control center personnel who monitor mission operations and equipment and who assist space crew. These monitoring agents can provide flexible services that are not provided by autonomous system management agents on a space vehicle. These agents watch for the occurrence of pre-specified patterns in telemetry data and perform selected actions (notes made in the console log, written reports, notification of people performing specified roles) when those events are recognized. We have prototyped tools to help flight controllers and engineers create, review and supervise these agents. We have developed a higher order specification interface for viewing original specifications and making new, similar specifications. We have studied an existing tool that performs similar functions in a control center, and have applied some of the lessons learned to our own work. This study has led to design of a new user interface for constructing and customizing agent instructions.