I claim the ornamental design for a tool organizer, as shown and described.
FIG. 1 is a front perspective view of a tool organizer showing my new design;
FIG. 2 is a back perspective view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top perspective view thereof, with the tool organizer open and with a zipper shown in broken lines;
FIG. 6 is a second top perspective view thereof, with the tool organizer open and with exemplary tools contained therein and the zipper shown in broken lines; and,
FIG. 7 is a bottom view with the tool organizer closed and with treads shown in broken lines.
Features shown in broken lines form no part of the claimed design.