How long should a employment reference letter be?

Hi

I have read about the info that should be in the employment reference letters. I am just wondering how long these letters should be? For example, how long should a reference letter be for 2 years of work? How much detail about the responsibilities should the employer go into?

Will there be any issues if the letter is more than 1 page?

Another question I have is this: should a brief description of the evidence be included for each section of the application. Eg. Should I state in the earnings section that I have included payslips, tax forms, bank statements and that I earned X amount and that I am applying for X points? Or should I just include the evidence and let the caseworker work it all out? I feel I should make it easy for the caseworker and include summaries of each section, but I dont want to make the caseworker feel like I am trying to fool them.

Any ideas/opinions?

I know its a bank holiday in the UK.....

Nobody got any ideas for me?