For the Cookies, mix flour and 1/4 teaspoon salt in medium bowl. Set aside. Beat butter and granulated sugar in large bowl with electric mixer on medium speed until light and fluffy. Add egg, lime peel, extract and sage; mix well. Gradually beat in flour mixture on low speed until well mixed. Divide dough in half. Form each half into a log about 9 inches long and 1 1/2 inches in diameter. Wrap in wax paper.
Refrigerate 1 hour or until firm.
Preheat oven 350°F. Mix sanding sugar and kosher salt. Roll each cold dough log in mixture to coat evenly. Cut dough into 1/4-inch thick slices. Place on ungreased baking sheets.
Bake 12 to 15 minutes or until lightly browned around edges. Cool on baking sheets 1 minute. Remove to wire racks; cool completely.
For the Tequila Glaze, mix confectioners’ sugar, water and tequila in small bowl until smooth. (Or omit tequila and use 2 tablespoons water.) Drizzle Glaze over cooled cookies. Let stand until glaze is set.