Could you provide more details on your use case? AdWords will try to
remove invalid clicks from reports, if that's what you are asking. If you are trying to determine if a GCLID is invalid you could compare it to the GCLIDs in the
Click Performance Report, but there will be
a delay. In addition, AdWords may detect that a click is invalid a few days after it occurred, so you would need to rerun your report a few days later if you needed 100% accuracy.
If I haven't answered your question please provide some more information on what you are trying to achieve.