Tooled coins are coins that have suffered from modern re-engraving in a misguided effort to "improve" them. Tooled coins should be avoided. A untooled ancient coin, no matter how poor the condition, is preferable to a tooled (spoiled) coin. Tooled coins may be recognized by the following:
3. The details are often incised, rather than in relief. For example, the details of the hair, a laurel wreath or drapery on a tooled coin often consist of simple lines cut into the original worn surface. These details may look original at a glance but the difference between incised and relief details is often easily detected with a careful examination.
5. The style of lettering may be different from the original. Tooled lettering may rise more vertically from the field of the coin than on untooled coins. Tooled lettering is often uniformly wide and the top surfaces of letters are flatter than normal.
If you suspect a coin has been tooled, you should compare it with un-tooled coins of the same type.
See other examples of tooled coins in the fake coin reports: http://www.forumancientcoins.com/fakes/thumbnails.php?album=23
The use of tools on blown glass.