"To insure the agreement" means to ensure or guarantee that a promise or understanding is upheld or followed through. It is like buying an insurance policy to protect your agreement from being broken. Full definition
There are two main types of insuring agreements: all - risk coverage and named - perils coverage. (pocketsense.com)
Read the terms and conditions listed on the auto insuring agreement before signing it. (autos.com)
The policy's insuring agreement provided coverage for «all risks of direct physical loss of or damage to the property insured» subject to exclusions in the policy. (theallgrouponlinejournal.com)