IMHO all good company cell phone policies have a compelling business reason why someone would get a company cell phone. The most likely reasons are that they go to people who travel and must be in contact with staff and available to staff at least 18 hours a day. If we provide a cell phone we let the person know they will be available on weekends and on vacations. This reduces the number of people who request and even I do not have company cell phone.
I think everyone should get a laptop if possible. Companies get their money back in productivity when you give someone a laptop and provide them with secure access. They respond to emails faster and tend to do more work - according to studied. If you have more limited funds then use the criteria for cell phones.
The two big things are that(1) the cell phone or laptop can not be used by strangers/family members etc. If this rule is broken, they should be subject to termination. (2) If you break the cell phone or laptop you are subject to (we say) up to 75% of the cost of repair or replacement. I have never charged anyone 75% but I did charge one person 50% because they ran over the laptop with their luggage bag.