Though portions of the Agenda are published in Collected Works of the Mother Volumes 10 and 11, yet there are interesting links which one can find only in the Agenda. The Agenda describes aspects of sadhana during the physical transformation and portions of Her life as connected with this work.
It is best to read it after one has read most of Her earlier works, at least the Conversations and Prayers and Meditations. To read it prematurely (or limit oneself to reading only Agenda) may get an erroneous impression of what the yoga is about.
It is also necessary to remember that the Agenda contains quite a few remarks and impressions of Satprem to which the Mother responds in a certain contextual way, as well as Her remarks about some disciples about whom the Mother has said very different things at different times. Reading about them only through the Agenda gives a very skewed idea about them.
The last part about the Mother’s physical withdrawal was written by Satprem in a state of personal anguish and anger and hence should not be taken as a gospel of Truth. He was not personally present during the last 6 months and the account of those present and intimately involved is different in many respects.
All in all it is a gold mine but due to the very nature of the conversation, mainly with one particular disciple, one needs to use the discernment to discard the mixture which is often gets blended with the conversation or is prompted by the disciple with a clear motivated intention. If one can discern between the two and keep mainly to Her Yoga and Life as recounted in the Agenda then it is no doubt a very useful document.