I usually write all/most of the job descriptions for companies I've worked for. I make an absolute point of not having "any other duties" in MY job description.
"Any other duties" gives your employer a licence to screw you and dump the body. I advise staff that I will delete this clause from their JD as well, provided they put in the yards to make the JD accurately reflect their duties, and their boss must sign off on it. This is an enormous benefit come performance assessment time.
As a corporate services manager, if something doesn't fit neatly into one work area category or another, it gets flung my way. I get out my JD and my pay slip and explain that to make these balance either: 1. they delete something else from the JD (after all, this is the contractually agreed Statement Of Work); 2. They increase the pay slip; or 3. I go.
Mostly they pay, sometimes I go, but they never decrease the JD.
SUMMARY: NEVER put "Any other duties" in your job description, and encourage others to also develop meaningful JDs.
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