In the wake of growing criticism over conditions at Rikers Island, Mayor Bill de Blasio enacted legislation on Thursday to boost oversight of the use of solitary confinement at the jail.

The law, which was passed by the City Council last week, will require the Department of Correction to publish quarterly reports detailing the number of inmates in solitary confinement, their length of stay and whether they were injured or assaulted. But it does not include any provisions that would directly curtail guard brutality or, as inmate advocates have long hoped, the use of isolation as punishment.

Mr. de Blasio said the law would “help us to manage the jails more effectively and address the problems that were left to us.” The first report is due in January.

At Rikers, solitary confinement, also known as punitive segregation, is used to discipline inmates who violate jail rules. Inmates are locked in small cells for 23 hours a day and have almost no human contact besides short interactions with the jail staff. Inmates are given an hour of recreation time per day, which they are allowed to spend outside shackled and in small cages. Some inmates spend months locked away.