Keeping in mind that the index level is the most robust level of interpretation, there are a couple of notable changes in subtest scores, though most of them are fairly consistent from test to test. Also, as general commentary, though I don't, of course, have any direct observational data on this, it doesn't look like he was too affected by the timing of testing, as the tasks that are usually most sensitive to inattention and fatigue (WMI & PSI) are generally average or above, and uniformly higher than on previous testing, where comparisons are possible.
At the index level, he has a pretty clear, consistent pattern of personal and normative strength in the language area, and average skills in the nonverbal areas. His strength area is very suited to traditional school expectations, especially in the primary years, when language has an even larger role than it does later on, and is in a range often described as optimal intelligence--strong enough to excel and be appreciated by educators, but not so far out of the norm that systems struggle to provide appropriate supports.
The changes at the index level are not extremely significant, except in PSI, which rose markedly, though they do result in nominal changes in classifications (High Average to Average, Low Average to Average). Without some clinical/test observations, there is not an obvious specific explanation for the lower VP and MR scores, though in general, first grade scores are less stable than third grade scores. The PSI changes are easier to understand, as CD is a different task at the two ages, and SS likewise is a slightly different task. Also, many young children lack the fine motor skills to efficiently complete the PSI subtests, with the wide range of NT fine motor development adding a layer of variability to those scores. They may also be unfamiliar with timed tasks, and lack a sense of urgency.
I will note that the most fine-motor-involved task on the test is also where his lowest score is (not horrible, but in the Low Average range). That is probably the primary area I would keep an eye on, as it is also consistent across test administrations. With regard to the lack of effort, it is possible that it is temperamental, that it is developmental, or any number of other reasons, but it is also possible that he finds handwriting just laborious enough that extra written output is aversive. If handwriting or other hand skills are significant concerns across settings and tasks, you may wish to consider consulting with an occupational therapist about fine-motor skills.
You may also wish to go back to the school psych who administered the test and ask these same questions, as they will be in a better position to comment on test observations.
