This will add the ability for an External basic LTI tool to put grades in the Sakai grade book using web services. This will only be possible if the administrator and instructor configure the tool placement to accept grades and the tool will only be able to place grades in the column chosen by the instructor. This will be based on a simple profile / binding of the IMS Learning Information Services.
I attach several design documents and you can get general information about the Basic LTI Specification here:
Please take a look at this design and let me know what you think.