Yes, it is very important for the reference letters to substantiate what you claim as your job duties. Equally important is to describe your job duties in the "Schedule 3" closely in line with HRSDC description of the NOC your job falls under. Here are couple of examples from my application that may be useful to the new applicants:
1)NOC4166 description by HRSDC: "Education policy researchers, consultants and program officers perform some or all of the following duties:
•Conduct research, produce reports and administer education policies and programs
•Evaluate curriculum programs and recommend improvements
•Develop the structure, content and objectives of new programs
•Conduct statistical analyses to determine cost and effectiveness of education policies and programs
•Provide ongoing professional development, training and consultative services to teachers and other professionals throughout the public and private sector
•Develop teaching materials and other resources for program delivery
•Deliver presentations at conferences, workshops and symposia
•May supervise the work of other education policy researchers, consultants or program officers
•May administer specialized testing and assessment programs."
My wording: "Expert-consultant, Edu.: >Provide consulting services in developing structure, content & policies of new prog's; >assist institutions to prepare for 3rd party accreditations; >provide prof. development workshops to various professionals."
2)NOC4011 description by HRSDC: "University professors and lecturers perform some or all of the following duties:
•Teach one or more university subjects to undergraduate and graduate students
•Prepare and deliver lectures to students and conduct laboratory sessions or discussion groups
•Prepare, administer and grade examinations, laboratory assignments and reports
•Advise students on course and academic matters and career decisions
•Direct research programs of graduate students and advise on research matters
•Conduct research in field of specialization and publish findings in scholarly journals or books
•May serve on faculty committees dealing with such matters as curriculum planning and degree requirements, and perform a variety of administrative duties
•May represent their universities as speakers and guest lecturers
•May provide professional consultative services to government, industry and private individuals.
University professors and lecturers specialize in a particular subject matter such as biology, chemistry, anatomy, sociology, business administration or law."
My wording: "F/T University Faculty: Taught graduate and undergraduate business courses; >prepared & delivered lectures; >designed, administered & graded exams & assignments; >supervised Master's thesis; >provide consultative services to org's; >worked in committees."
good luck...