A duty description separating teaching, research and any clinical activity with approximate time allocations, the reporting and supervisory structure, the funding source, and any expected licensure or credentialing steps with their timing.
Ask for a description that separates the components
A single paragraph combining all three activities makes review harder and can obscure a clinical assignment the physician has not fully registered. Requesting the components separately is a reasonable administrative ask, and departments accustomed to international appointments often have templates. Where a grant funds the position, the grant terms may describe the research obligations more precisely than the appointment letter does.
Ask for the description on institutional letterhead, signed by someone with authority over the post, rather than as a forwarded email chain. Where a department is unwilling to allocate time in writing, that reluctance is itself information worth reporting to counsel. Hypothetical example: a medical laboratory technologist recruited to the same research programme has a comparatively simple document set, because that profession appears on the USMCA professions list and the file is mostly about the credential, whereas the physician's file is mostly about the duties.
Ask that the two descriptions stay separate rather than accepting one combined letter for the group, since a group letter tends to describe the programme's needs instead of each person's work. If a grant funds part of the post, request the section of the grant that sets out the research obligation, together with its start and end dates.