Cyrus is object not subject, and μεταπεμπεται is middle (as usual) not passive. “He (Artax.) sends for Cyrus …” Then the subject of εποιησε and απεδειξε (actives, not passives as you translate) is also Artaxerxes. By mistaking the construction you made it unintelligible. Tolmides should be accusative in the first sentence, and like Cyrus should be repeated in the nominative in the 2nd, since the subject has changed.
Yes, very true. I meant to correct that in the revision. However I tried to follow Σωκράτους for Τολμίδους. But looking at usage for the name in Anabasis, I now see that I mistook it again, it should be:
Τολμίδην δὲ μεταπέμπεται…
Τολμιδους would imply root Τολμιδεσ- I assume.
But I think that I made the original mistake changing Τολμίδην to nominative in the first place because I was reading those in my head as passive forms, just as you say.