Developers use it to poll readers, checking for the presence of a card and automatically connecting to it upon insertion.
The file is a specialized utility primarily used for managing, configuring, and troubleshooting smart cards and their associated reader hardware. It is often bundled as part of a software package for smart card programmers, signature verification systems, or reader diagnostic suites. Primary Functions and Features
If cardtool.exe is consistently using a high percentage of your CPU (over 20–30%) while no card reader is in use.