The ICC set May 1 this year to Dec. 31, 2016 as the qualification period.
Some teams play more than others, a handicap for low-ranked teams such as New Zealand, Bangladesh and Zimbabwe, and Richardson said the ICC has yet to set a minimum number of tests required to gain enough points in the rankings to finish among the top four.
Graeme Smith, captain of top-ranked South Africa, who was accompanied by Pakistan captain Misbah-ul-Haq, said the world test championship has added more meaning to all and future test series.
"It's fantastic to have a pathway clearly identified for the world test championship and to know that the top four teams will have a chance to battle it out to be crowned the ultimate champions," Smith said.
Misbah said he would like to see a longer championship instead of a format offering two semifinals and final.
"If you have some time and you want people to enjoy test cricket you need to give equal chance to all the teams, like they could play against each other and then you go for semifinal and final," Misbah suggested.
"People want to see test cricket and if you have only three games it won't work."
Misbah has quit playing Twenty20 internationals, but still leads Pakistan in tests and one-day internationals at 39.
He said the shortest format as one of the reasons for the reduced popularity of test cricket.
"Twenty20 cricket is dominating nowadays, but this (world test championship) will generate some sort of interest among players," he said.
"Winning a World Cup is something different. You can be No. 1 for some time and then you can just drop to No. 2 or No. 3, but once you become world champion, it means a lot to you."