Is it possible to print result of .TF or .PZ analysis in Xschem schematics like annotate_op?

Yes, there is a command to do that in ngspice manual. Check it out

Thanks, I can print it in Ngspice command line or transfer values to .op plot for back annotation. Unfortunately, poles are sorted in descending order and are more than expected; seems there is no simple way for handling poles and zeros.