Formalisms for representing communication in agent theory have tended to be based on speech act theory, as originated by Austin [Austin, 1962], and further developed by Searle [Searle, 1969] and others [Cohen and Levesque, 1990a][Cohen and Perrault, 1979]. Briefly, the key axiom of speech act theory is that communicative utterances are actions, in just the sense that physical actions are. They are performed by a speaker with the intention of bringing about a desired change in the world: typically, the speaker intends to bring about some particular mental state in a listener. Speech acts may fail in the same way that physical actions may fail: a listener generally has control over her mental state, and cannot be guaranteed to react in the way that the speaker intends. Much work in speech act theory has been devoted to classifying the various different types of speech acts. Perhaps the two most widely recognised categories of speech acts are representatives (of which informing is the paradigm example), and directives (of which requesting is the paradigm example).
Although not directly based on work in speech acts, (and arguably more to do with architectures than theories), we shall here mention work on agent communication languages [Genesereth and Ketchpel, 1994]. The best known work on agent communication languages is that by the ARPA knowledge sharing effort [Patil et al., 1992]. This work has been largely devoted to developing two related languages: the knowledge query and manipulation language (KQML) and the knowledge interchange format (KIF). KQML provides the agent designer with a standard syntax for messages, and a number of performatives that define the force of a message. Example performatives include tell, perform, and reply; the inspiration for these message types comes largely from speech act theory. KIF provides a syntax for message content - KIF is essentially the first-order predicate calculus, recast in a LISP-like syntax.