Hi Spyros,
Thanks for your questions - keep 'em coming!
You are correct about the extremely open-ended nature of the validation game(s) and action verbs.
These were chosen as deliberate features of the competition in order to encourage people away from the various levels of hard-wiring/bias which often dominate.
What I can say is that:
a) There will likely be at least two games in the evaluation
b) It would be reasonable for agents to include the kind of bias that a human adventure game player would have (e.g. knowledge of common verbs such as get/take/drop/verbose/inventory etc). Not all of these are guaranteed to work on any given game, though.
Hope that helps.
Best wishes,
Jerry.