In traditional histories, he was praised for his integrity but blamed for faulty decisions that led to the imperial government's loss of control over the circuits north of the Yellow River.
In 812, in addition to being imperial scholar, he was moved from the You Bujue post to be Sifeng Yuanwailang (司封員外郎), a low-level official at the ministry of civil service affairs (吏部, Lìbu).
[5] In 814, when Emperor Xianzong was in the middle of a campaign against the warlord Wu Yuanji, who controlled Zhangyi Circuit (彰義, headquartered in modern Zhumadian, Henan), the pro-campaign chancellor Li Jifu died.
Viewing this as a criticism against himself, Emperor Xianzong demoted Zhang, but nevertheless changed Li's posthumous name to Zhongyi (忠懿, "faithful and benevolent").
[5] It was deputy chief imperial censor that in 818, he submitted an indictment against the eunuch Yang Chaowen (楊朝汶), who had arrested over 1,000 people for allegedly owing money to the palace.
As a result of the indictment that Xiao submitted, which the chancellors Pei Du and Cui Qun also supported, Emperor Xianzong ordered Yang to commit suicide.
He was also said to be filially pious, and he served his mother Lady Wei carefully as an ordinary son would despite his honored chancellor status.
[11] In spring 821, Wang Bo the military governor (jiedushi) of Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan) submitted much tribute to Emperor Muzong and also bribed the powerful eunuchs, hoping to be chancellor.
After Wang was summoned to Chang'an, Xiao was removed from his chancellor position and made You Pushe (右僕射), one of the heads of the executive bureau (尚書省, Shangshu Sheng).
As the minister of civil service affairs required conducting much tedious work, Xiao felt the position unfit for his lifestyle, and also declined it.
As he still considered Luoyang to be too busy of a place, and particularly did not want to be receiving guests all the time, he went to live at his vacation mansion at Jiyuan, and it was said that he enjoyed life in the hills.