Holacracy Community of Practice Archive, 2015-2019 Community Holacracy Web Site

Technically, only admins can add “global checklist” and “global metrics” (it applies for all the circles of the organization). 

Each person can add checklist items in his/her roles but if you want to add it on another role you're not assigned to, you need to ask that role to add it.

The secretary can modify that but only because it could make sense to do that in a middle of a meeting - in the constitution there is nothing special for the secretary. And, of course, admins can do that as well.