Important parameters are the retention time, peaksymmetry and theoretical plates and maybe resolution. Every column comes with an attached quality certificate where these parameters were tested. Exact measuring conditions and sample amounts are mentioned on the certificate. The column parameters can easily be checked by re-running the standard test shown in the enclosed chromatogramm.
If you do not have the possibility to re-run the KNAUER standard test, you can also use other suitable substances and define your own parameters and criteria for evaluation.