Determines how many attributes of a composite object are described.
*describe-length* controls how many attributes of a composite object the function describe describes.
This means the number of elements of a sequence, entries in a hash table, slots of a structure instance, and so on.
nil then describe describes all of the attributes. Use this value only with care.
The describe functionality is load-on-demand in the LispWorks image as shipped. Therefore if you have not done
(require "describe") or called describe,
*describe-length* may be unbound.
LispWorks User Guide and Reference Manual - 13 Feb 2015