More accurately document buildInfo's effect on up-to-date checking

Closes gh-13152

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/asciidoc/integrating-with-actuator.adoc

@@ -51,11 +51,11 @@ include::../gradle/integrating-with-actuator/build-info-custom-values.gradle[tag
 ----
 
 The default value for `build.time` is the instant at which the project is being built. A
-side-effect of this is that the task will never be up-to-date and, therefore, builds will
+side-effect of this is that the task will never be up-to-date. As a result, builds will
-take slightly longer as more tasks will have to be executed. Another side-effect is that
+take longer as more tasks, including the project's tests, will have to be executed.
-the task's output will always change and, therefore, the build will not be truly
+Another side-effect is that the task's output will always change and, therefore, the build
-repeatable. If you value build performance or repeatability more highly than the accuracy
+will not be truly repeatable. If you value build performance or repeatability more highly
-of the `build.time` property, set `time` to `null` or a fixed value.
+than the accuracy of the `build.time` property, set `time` to `null` or a fixed value.
 
 Additional properties can also be added to the build information: