Source: Unearthed Arcana 15 - Feats

You pride yourself on your quickness and your close study of certain clandestine activities. You gain the following benefits:

• Increase your Dexterity score by 1, to a maximum of 20.

• You gain proficiency with thieves’ tools. If you are already proficient with them, you add double your proficiency bonus to checks you make with them.