I disagree. I assert that player agency only requires the player to be able to state an in-game narration of intent, and that intent has a mechanical resolution possible when there is conflict as to its success. (i.e., the DM advice "Say Yes or roll the dice.") The right the player has to assert any particular "type" of resolution mechanic is controlled by the rules. The entire job of the DM and the rules, working in concert, is to map the stated intent to a particular resolution mechanic. As long as the player can assert intent for the character, he maintains agency.
Please assert where you have definitional disagreement.