Hi Cas21
I don't know which benefit you are looking for information about telephone assessments. I have put links below.
For PIP Guide:
In the Guide to PIP claims and Reviews - it has information about telephone assessments from pages 107 - 118. In those pages, it lists the different topics that you may be asked at an assessment
benefitsandwork.co.uk/guides-for-claimants/pip For ESA and UC Guides
ESA and UC Claims for Physical, Mental Health and Learning Difficulties: a guide to the limited capability for work assessment.- it has information about telephone assessments from page 114 - 122 - In those pages it lists the type of questions you may be asked at an assessment.
benefitsandwork.co.uk/guides-for-claimants/esa I hope this helps
BIS