The Collaborative International Dictionary of English v.0.48:

Communicatory \Com*mu"ni*ca"to*ry\, a. [LL. communicatorius.]
   Imparting knowledge or information.
   [1913 Webster]

         Canonical and communicatory letters.     --Barrow.
   [1913 Webster]

WordNet (r) 3.0 (2006):

communicatory
    adj 1: able or tending to communicate; "was a communicative
           person and quickly told all she knew"- W.M.Thackeray
           [syn: communicative, communicatory] [ant:
           incommunicative, uncommunicative]