I just happened to read a passage defining agent-hood (kartṛtva):
Agency is the fact of having a direct knowledge of the material causes, of having desire to do and of being endowed with an [actual] action
The text is Annambhaṭṭa's dīpikā on his Tarkasaṅgraha (on proposition 17). The context is that of the inference about the existence of a Lord, namely "A sprout is made by a doer, because it is a product, like a pot", so that the agency here described might be only the God's one. If this were not the case, one would have the following three requisites of agency in general:
- 1. direct knowledge of the material causes (i.e., applied and unmediated knowledge)
- 2. desire to do
- 3. actual doing
As for 3., I would define free-will as just the capacity to do what one wishes, independent of whether one actually does it or not. But the stress on the actual action might be just a nicety of Annambhaṭṭa.
The cognitive element seems a more significant difference. The material causes are later defined as samavāyikārana (like clay in case of a pot). Direct knowledge is a typical requisite of God, since He does not need to depend on the complex epistemological system we are bound to, and can just know everything directly. If the definition does not only apply to Him, then it means that agency requires this sort of direct knowledge to the things you'll need in order to act. Does it refer only to practical actions, such as doing a pot, where you must have a direct knowledge of the clay? Or can it apply also to general concepts? And what would a "material cause" be, in such cases?