This is stated on the website of the President of Kazakhstan
“The following documents were signed as part of the state visit of the President of the Republic of Kazakhstan, Kassym-Jomart Tokayev, to the People's Republic of China:
5. Agreement between the Government of the Republic of Kazakhstan and the Government of the People's Republic of China on mutual exemption from visa requirements”.
The Visa Waiver Agreement assumes that citizens Kazakhstan and China will be able to visit these countries without a visa for a period not exceeding 30 calendar days from the moment of crossing the state border (total 90 calendar days within 180 calendar days).
Mutual Release Agreement visa requirements apply only to tourist and business trips, special visas will still be required for work.