To Modify the Description of a Block
Use this procedure to add or modify the block description that is displayed in DesignCenter.
Click
Insert tab
Block Definition panel
Create Block
.
In the Block Definition dialog box, in the Name list, select the block for which you want to modify the block description.
In the Description box, enter or modify the description of the block.
Click OK.
In the Block - Redefine Block dialog box, click Redefine Block.