You are right, AIS and TIS should also be checked. I have not been keeping up with these developments, so I was still checking my 26AS only.I read in some article that this year onwards you should also check the AIS and TIS reports from IT department website else could get a notice if any mismatch.
Earlier just checking 26AS was enough I guess?
Unfortunate though that AIS and TIS are not available as Excel/CSV. I hope they add this next year.