In his Nyāyamañjarī, Jayanta discusses various Prābhākara views about the way orders function. According to the first group, the prescription (i.e., order) itself has to be performed. There is hence no need for something else (namely, the action) to be conveyed by the same verbal ending. The order requires an object to be performed, but that object is the order itself. Hence, if I am not wrong. "cook!" would only require the execution of the order. That the order regards the action of cooking is something one understands out of one's background and contextual knowledge. The idea of a single level works nicely for sentences which only have a linguistic dimension, such as "I baptize you…":
The mainstream Prābhākaras, on the other hand, claim that the prescription is understood by each of its listeners as something to be done. And this "to be done" cannot but consist in an action:
Also in its (the prescription's) regard, there are two different opinions. Some admit that language consists of impulsion. Only the prescription has to be performed, because it is understood in this way through the verbal endings of optative etc., because no other duty is understood, and because of the extreme feebleness of the thesis according to which the duty is the sheer meaning of the verbal theme.
Hence, [the prescription] has to be done.
Others, by contrast, resort (saṃśrī-) [to the view] that the [injunction] induces [people] to undertake actions, since the injunction (niyoga) is apprehended (pratī-) as something to be done. The duty, once understood, enjoins [each] person to its own realisation. In fact, once he has understood "this has to be done by me", a person undertakes an action for the sake of its realisation.
For further references to posts dedicated to Jayanta and to his linguistic theories, see here. On duty in Prābhākara Mīmāṃsā, see here and here. On how Sacred texts can convey their orders according to the Prābhākaras, see here.