I am wondering if feedback to wallet-users from Michelson contracts has been considered previously in the development of Tezos, and where is it / why is it not being considered ?
I am thinking it would be useful to embed in Michelson a way to provide human-readable feedback in the form of strings. (The main purpose would be to produce feedback in a wallet app; but maybe it could be used for debug/test as well. There is a mechanism for error messages, but there I can't see anything that seems to support information and warning messages.)
Just to clarify a few points of what I'm thinking:
Contract feedback does not offer any security per se, but it could allow users to check if they input their parameters correctly, and it could provide some warnings e.g. an underlying contract could notify if entry-points are accessed by intermediary contracts rather than directly.
The contract output messages could be solely for simulation as it is not really necessary to put the results in storage, therefore it can also be omitted during block production and it should consume a very minimal amount of gas.