Self assessed skills matixes are worth the bits they're written on.
Ditto self-written recommendations and self-written assessments.
I was once asked to write my own reference after I had requested one in an exit interview. I said that if my boss couldn't be arsed to write a paragraph saying I was or was not worth what he'd paid for me then I didn't want it anyway.
I was also once asked to write my own yearly assessment by a boss eager to try "new methods" of staff management. I wrote that I was a genius, always knew the right answer to any problem and was overdue for promotion and/or a significant pay raise. No-one was ever asked to write their own assessment again.
Since there was no chance of promotion (or that mythical thing, a raise) anyway there was no need for me to pull punches. My lazy-assed boss needed to be told to stop sitting around all day reading the paper and eating crisps, and do what he was paid to do. One task on his list was write yearly assessments for his staff and since they regularly made him look good despite himself he should have been happy to do that.