So you could make a checklist of things like is it ?: appealing to children, durable safe age appropriate developmentally supportive ( I would elabaorate on this by looking at each developmental area and/or at specific things like how a climbing frame could support gross motor skills say) realistic (in the case of something representing real things like kitchen equipment say)
Gender, ethnic group and special needs etc friendly fun educational value ( a jigsaw could help with colour recognition say)
Also is it value for money
Is it limited in use (needs a lot of space or awkward to put up say)
Then you could mark the checklist Y/N and have a comment box for each thing where you briefly explain why it's Y/N)
As to the actual form of the piece I imagine you have been given how they want it laid out but it's usually something like
SCENARIO (sometimes this heading is omitted and aim is included with intro)
My aim is to select a toy and develop a range of criteria by which it will be assessed.
INTRO what you are going to do (see scenario above)
Why you are doing it and why you picked this toy how you are going to do it (Observe children playing with it and look at price, safety etc)
CHECKLIST
The criteria above, yes/no and a comment
EVALUATION
What you found and how your findings are good or bad.How they support development, again I would break into areas, durable, good/poor value for money etc.
RECOMMENDATIONS
What you found that could be inproved and how eg child in wheelchair can't access sand box on stand so I will move to a wheelchair accessible table. it breaks very easily so I will look into a better quality product.
PERSONAL LEARNING what you have gained/learnt from doing this