  Asteroseismology is a unique tool that can be used to study the interior of
stars and hence deliver unique information for the studiy of stellar physics,
stellar evolution, and Galactic archaeology.
  We aim to develop a simple model of the information content of
asteroseismology and to characterize the ability and precision with which
fundamental properties of stars can be estimated for different space missions.
  We defined and calibrated metrics of the seismic performance. The metrics,
expressed by a seismic index ${\mathcal{E}$ defined by simple scaling
relations, are calculated for an ensemble of stars. We studied the relations
between the properties of mission observations, fundamental stellar properties,
and the performance index. We also defined thresholds for asteroseismic
detection and measurement of different stellar properties
  We find two regimes of asteroseismic performance: the first where the signal
strength is dominated by stellar properties and not by observational noise; and
the second where observational properties dominate. Typically, for evolved
stars, stellar properties provide the dominant terms in estimating the
information content, while main sequence stars fall in the regime where the
observational properties, especially stellar magnitude, dominate. We estimate
scaling relations to predict ${\mathcal{E}$ with an intrinsic scatter of around
21%. Incidentally, the metrics allow us to distinguish stars burning either
hydrogen or helium.
  Our predictions will help identify the nature of the cohort of existing and
future asteroseismic observations. In addition, the predicted performance for
PLATO will help define optimal observing strategies for defined scientific
goals.
