Re^2: Annual Self Appraisal forms and all this (censored)

[Aristotle]

No, you shouldn't be honest. At all.

These things will be filed with your paper trail. However good your current standing is, writing about failures of your own on such a form creates skeletons in the closet that might be pulled out to be used against you two years down the line when an unrelated disagreement puts you in a position of adversity.

Pile the praise on yourself. Don't talk about failures.

(Again, this assumes a large corporate setting. In a small shop with good atmosphere and direct wires between everyone a formal process like this is out of place.)