For both councillors and the public to know what is to be discussed and agreed at a meeting there needs to be clarity on the agenda and "matters arising", just like "any other business" are not clear enough so yes, considered inappropriate for a council agenda. However, a follow up on decisions taken at a previous meeting can be helpful. Some councils allocate a specific agenda item as a follow up along the lines of "update on xyz" which is best practice but can make for a rather dauntingly long agenda. Others use something along the lines of "clerk's report" so that the clerk can report on actions that he/she has done to complete the decisions taken at the previous meeting, provided it is recognised that no decisions can be taken unless that decision is clearly identified on the agenda.