Carbide Create uses a .csv file for tools:
number,vendor,model,URL,name,type,diameter,cornerradius,flutelength,shaftdiameter,angle,numflutes,stickout,coating,metric,notes,machine,material,plungerate,feedrate,rpm,depth,cutpower,finishallowance,3dstepover,3dfeedrate,3drpm
525,Amana,45525,,45525,end,1.125,0,0.5,0,0,2,1.5,,0,,,,30,60,18000,0.02,,0.1,20,60,10000
390,Kyocera,1/8" 90 degree Kyocera V endmill,,1/8" 90 degree Kyocera V endmill,vee,3.175,0,2.244,0,90,2,38.1,,1,,,,203.2,254,10000,1.27,,2.54,20,254,10000
which can be edited in a text editor or spreadsheet and saved out again as a .csv
Some folks have been working on converting from one tool library to another:
perhaps the file formats are similar?