Trustee powers are powers that a trustee is granted by the terms of the trust. Trustee powers specifically state what the trustee has the right to do and to not do. Trustee powers are given to the trustee by the grantor or creator of the trust.
In the context of the law, trustee powers are legally binding, and the trustee has full legal authority to exercise them.
Trustee powers commonly include things such as the right to buy, sell or otherwise manage assets; the right to distribute assets to beneficiaries; the right to hire or fire advisers, etc.
Trustee powers can represent the control of assets that are worth substantial amounts of money. So, people who make trusts often consider these powers very carefully before giving them to the trustee. If a trustee abuses or goes beyond his or her powers, then legal action can follow.