If you study Rangu:

[You can GIVE WEAPON/TOOL TO THE CLERK to repair it.]
[You can GIVE a container of weapons or tools to the CLERK to repair it.]
[You can ASK CLERK ABOUT REPAIR ALL to repair all worn and held items.]

Was the 2nd option ever implemented? I tried multiple containers (including the one he'll give you if you ask him for a sack) and all the syntax combinations I could think of but I was unable to get him to accept a container of tools to repair all at once.