Most information in a federal employee's personnel file is exempt from disclosure under FOIA because of restrictions both in FOIA itself and in the federal Privacy Act of 1974. Unless the disciplinary action was public, e.g. the result of a court case, a member of the public is unlikely to get that information. The Office of Personnel Management (OPM) is the agency that has oversight of release of federal government employee personnel records. Most of the employee's records are not subject to disclosure, including records of job performance appraisals. Under its regulations, the following is the information from an empoyees Official Personnel Folder (OPF) that is routinely subject to disclosure under FOIA:

§ 293.311 Availability of information.

(a) The following information from both the OPF and employee performance file system folders, their automated equivalent records, and from other personnel record files that constitute an agency record within the meaning of the FOIA and which are under the control of the Office, about most present and former Federal employees, is available to the public: 

(1) Name; 

(2) Present and past position titles and occupational series; 

(3) Present and past grades; 

(4) Present and past annual salary rates (including performance awards or bonuses, incentive awards, merit pay amount, Meritorious or Distinguished Executive Ranks, and allowances and differentials); 

(5) Present and past duty stations (includes room numbers, shop designations, or other identifying information regarding buildings or places of employment); and 

(6) Position descriptions, identification of job elements, and those performance standards (but not actual performance appraisals) that the release of which would not interfere with law enforcement programs or severely inhibit agency effectiveness. Performance elements and standards (or work expectations) may be withheld when they are so interwined with performance appraisals that their disclosure would reveal an individual's performance appraisal. 

(b) The Office or agency will generally not disclose information where the data sought is a list of names, present or past position titles, grades, salaries, performance standards, and/or duty stations of Federal employees which, as determined by the official responsible for custody of the information: 

(1) Is selected in such a way that would reveal more about the employee on whom information is sought than the six enumerated items, the disclosure of which would constitute a clearly unwarranted invasion of personal privacy; or 

(2) Would otherwise be protected from mandatory disclosure under an exemption of the FOIA. 

(c) In addition to the information described in paragraph (a) of this section, a Government official may provide other information from these records (or automated equivalents) of an employee, to others outside of the agency, under a summons, warrant, subpoena, or other legal process; as provided by the Privacy Act (5 U.S.C. 552a(b)(4) through (b)(11)), under those Privacy Act routine uses promulgated by the Office, and as required by the FOIA.

5 C.F.R. § 293.311.

In short, you are very unlikely to get the type of records you described. Like other citizens, federal employees have rights to privacy concerning the information that the federal government maintains about them. As a result, the information you get is pretty basic and not anything that would embarass the employee, subject him/her to harassment or violate the employee's basic rights to privacy under the Privacy Act.