The "insuring agreement" is found on the first page of the "coverage form." (Note that this is generally not the first page of the insurance contract; that will be the declarations page. The other forms follow in more or less random order.)
The insuring agreement tells you in general terms what the insurance policy covers--but it doesn't actually provide much information. A typical first sentence of the insuring agreement of a commercial general liability policy is: "We will pay those sums the insured becomes legally obligated to pay as damages because of 'bodily injury' or 'property damage' to which this insurance applies." You still have to look elsewhere to figure out what "bodily injury" and "property damage" mean; I have been involved in cases where the meaning of "legally obligated to pay" has been an issue; "damages" can also be a term of the art. And of course, the phrase "to which this insurance applies" means that the policy covers what it covers and doesn't cover what it doesn't cover.
The insuring agreement also states that the policy doesn't cover exclusions, which are listed elsewhere in the policy; that it provides coverage up to the policy limits, which are listed elsewhere in the policy; and so on.
Although every word of an insurance policy can be and probably has been litigated, disputes over the insuring agreement generally focus on the meaning of the word "occurrence," which might or might not actually appear in the insuring agreement. I will discuss some of those disputes in future posts. (Additionally, not all policies are occurrence based. In a different future post I will explain the difference between occurrence based and claims based policies.)