The document Settling the Revocable Trust in California - A Primer for the Non-Professional Trustee (Toews & Murphy, Inc.) describes the disclosure responsibilities of the successor trustee in rather clear terms for a revocable living trust.
First, it says
Since the early 1980s, revocable trusts have become popular as estate planning tools in California because (a) they usually avoid the need for court proceedings to settle the estate of the person who set up the trust (“settlor”) and (b) they usually avoid the need for the court appointment of a conservator in the event that the settlor is incapacitated. For these reasons, most professionally prepared estate plans for people with significant assets
use these trusts.
Given that this would apply in most cases, I will assume that the trust in question is this type.
The document states
the trustee is responsible for seeing to it that all required notices of
administration are given
As Dale M alludes to in his earlier answer
The trustee ordinarily consults with beneficiaries on the conduct of trust business – for example, on whether to retain or sell real estate or whether to cash in stocks, bonds or other investments. However, the trustee has sole authority to actually make decisions on these matters, subject only to the trustee’s duty to be fair, to follow any restrictions in the trust document and to act in the best interest of the beneficiaries.
However, in California (an maybe other states), there is a specific legal requirement that Giving Notices of Administration includes the following (from the same document):
The California Probate Code was amended in 1997 to require the trustee to give notice of administration to beneficiaries and legal heirs of the settlor upon the settlor’s death. The notice must be in a specific statutory format and must advise recipients that they are entitled to a copy of the terms of the trust if requested. Usually, these notices are prepared by the attorney representing the trustee and sent out to each heir and beneficiary together with a copy of the trust. (Prob. Code § 16061.7)
The Probate Code has the following provisions:
(b) The notification by the trustee required by subdivision (a) shall be served on each of the following:
(1) Each beneficiary of the irrevocable trust or irrevocable portion of the trust, subject to the limitations of Section 15804.
(2) Each heir of the deceased settlor, if the event that requires notification is the death of a settlor or irrevocability within one year of the death of the settlor of the trust by the express terms of the trust because of a contingency related to the death of a settlor.
Finally, to the point of the original question:
(g) The notification by trustee shall contain the following information:
(1) The identity of the settlor or settlors of the trust and the date of execution of the trust instrument.
(2) The name, mailing address and telephone number of each trustee of the trust.
(3) The address of the physical location where the principal place of administration of the trust is located, pursuant to Section 17002 .
(4) Any additional information that may be expressly required by the terms of the trust instrument.
(5) A notification that the recipient is entitled, upon reasonable request to the trustee, to receive from the trustee a true and complete copy of the terms of the trust.