This is Boeing Vol I 12 Dec 06
"Engine Anti–Ice Use
Engine anti–ice must be used during all ground and flight operations when icing conditions exist or are anticipated, except during climb and cruise when the temperature is below -40°C SAT."
This is a note from a different source confirming they want us to use eng A/I in the descent in an effort to prevent flameouts (by increasing bleed air extraction) that have occurred near convective activity. This note is specifically for the GE engines.
Note: Use of engine anti-ice in descent near convective activity applies even with SAT below -40°C.