To manage pacing... think about how the author narrates the story? Descriptive narrative slows down the pacing because narrative time stops to explain the story (especially character and worldbuilding). Action narrative speeds up the pacing because narrative time moves forward to advance the plot.
If the author wants to balance description and action, the author can use cinematic action narrative, narrating the description following the action. Action as the trigger, description as the consequence/ reaction/ effect.
Descriptive narrative slows down the pacing because narrative time stops to explain the story (especially character and worldbuilding).
Action narrative speeds up the pacing because narrative time moves forward to advance the plot.