The Federal Civil Service Commission has ended weeks of confusion by announcing a definite policy on student employment this summer.

Students who want to work in Washington as summer assistants or interns must apply on "Form 57" to the agency in which they want to work, a Civil Service official said yesterday. There will be no central clearing house, either for processing applications or publicizing job opportunities.

In a directive to all government agencies, John W. Macy, chairman of the commission, has urged a drastic cut in summer employment, in line with President Johnson's economy drive. Government agencies have also been forbidden to hire students whose parents are employees of the same agency.

Exams Not Necessary

Except for typists and stenographers, no exams will be necessary for employment; students need not take the Federal Service Entrance Examination (FSEE), since it will not be used in making selections. Students who have applied for positions designated "traineeships," however, should have already taken the student trainee exam, which has now been discontinued.

The Government spokesman pointed out that no exams have ever been required for jobs falling under "Schedule A," the category that includes many student summer jobs.

The confusion in local government and university offices stemmed from Congressional attempts to institute a national, competitive student exam and an appoinment system of hiring. Although a bill finally passed the House last December, the Senate never enacted it.