If I were Hood, I would have done the same. Would you trust Adolf Hitler if he offered you an agreement? Why would Hood, or any Confederate general trust Sherman? Many of the general officers knew each other before the war. They knew who they could trust, and who they could not. Sherman, as stated by his own ethical principles, could justify any action, even lying, if it helped him win the war. Sherman is not a Lee. The Union Army burned, plundered, and raped throughout the South. Why would Hood assume that Sherman only had the best interest of the civilians in Atlanta? Also, I do not know what Hood’s orders were. I doubt that he made such a decision without consultation.
And in the lead up to the war, when Sherman was the Superintendant of the Louisiana Theological Seminary and Military Academy, Beauregard and a number of others implored him to join the Confederacy...seems they liked and trusted him enough to ask him to join their ranks. Johnston never stopped respecting him, serving as a pall bearer at WST's funeral, and contracting pnuemonia because he refused to wear his hat.
Why should Sherman, or any Union general, trust Hood?