No, no...NO! You don't need a reset tool for your car. Only needed on '96-'98 850 and 70 series Volvos. (By the way, don't pay the guy on eBay for this information...below is all he's going to email you for your $$)
Here's what to do:

S/C/V70/S60 1999 - Reset Procedure

The ignition switch has three positions.
I,II and III visibly marked on the ignition switch.

1. Turn the ignition switch to position one (I).

2. The only indicator light illuminated on the dash panel will be the SRS light. During the process the car is not running.

3. Gently press and hold the trip meter reset button (trip 1 must be selected). This button will go in very slightly so do not push hard. Any movement will be hard to feel. The reset button on the information switch has no role in resetting the service light.

4. This is a two handed process. Hold in the trip mileage reset knob and turn the ignition switch to position two. Within 10 to 20 seconds the service light will begin to flash. Immediately release the reset button. You have only 10 seconds to do this once the service light begins to flash.

5. Turn the ignition switch to full off. You can now start the car and the service lamp should be reset.

6. Don’t forget to perform the prescribed service as outlined in your owner’s manual!

Regards,
MIJ

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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon