The document is evaluated by looking at four areas:
Content, Communicative Achievement, Organisation, and Language.
The section on CONTENT asks:
Is all the content relevant?
Is the essay balanced?
The section on COMMUNICATIVE ACHIEVEMENT asks:
Have the conventions of the communicative task been used effectively?
Is the register and tone are consistent?
Are the language choices sufficiently formal and appropriate? Are the opening and closing paragraphs appropriate?
The section on ORGANISATION asks:
Is the essay is well organised and coherent?
Are the different ideas clearly signposted throughout?
Are the paragraphs internally well constructed, and linked together appropriately?
The section on LANGUAGE asks:
Is there an effective range of vocabulary, including less common lexis,
Is there a wide range of simple and complex grammatical forms, and are they used with control and flexibility, particularly in terms of sentence construction.
This information can be extremely useful in trying to understand what an essay for the CAE requires.