What would be the absolute minimum that a LEED CS tenant agreement would have to specify to get some level of LEED certification?

WEP1 is the first hurdle - to get 20% water reduction you'd have to have a list of plumbing fixtures.

Minimum energy performance may be handled in my case by local code, which specifies International Energy Code, roughly equivalent to ASHRAE 90.1. Otherwise you'd have to specify ASHRAE 90.1.

In a "cold dark shell" you might have to specify minimum insulation levels.

What else?