CIA Director William H. Webster yesterday announced he has disciplined seven agency employes involved in the Iran-contra affair, dismissing two, demoting one and issuing letters of reprimand to four.

In a report issued in his name, Webster enumerated other steps taken during his first six months as director in what he hopes will be a final response to the arms-for-hostages scandal that has put the secret agency in the spotlight for more than a year.

"This has been a testing chapter in the history of the CIA," Webster's statement said. "I hope that the actions I have announced today will put this chapter behind us."

He said the measures are meant to improve the agency's performance, raise its credibility with Congress and strengthen internal controls on covert operations as well as the inspector general's office. The statement said efforts will be aimed at improving intelligence evaluation and reducing "political influence" on the agency.

But Webster's action drew immediate fire from Sen. Arlen Specter (R-Pa.), a member of the Senate Select Committee on Intelligence, who called it "insufficient. . . . Demotions and reprimands do not begin to address the problem. . . firings and prosecutions are needed to put people on notice by example."

Meanwhile, a CIA counsel's classified report of about 100 pages was given yesterday to the congressional intelligence committees, which had been urging Webster to move against those who had acted improperly.

Some congressional officials interpreted Webster's actions as a cautious, middle course, far short of a housecleaning but a demonstration that he views the Iran-contra misdeeds as serious.

But in an action that underlined its concern over the Iran-contra episode, the Senate intelligence committee yesterday approved a bill that would require the president to notify Congress within 48 hours of undertaking a new covert operation. In the most sensitive cases, the president would have to notify four leaders of Congress.

One source said the closed-door vote was heavily in favor of the bill. The administration strongly opposes any mandatory time limit for reporting, arguing that it would be an unwarranted invasion of the president's constitutional prerogatives to make foreign policy. Officials have said Reagan would likely veto such legislation.

The Senate is scheduled in January to take up the bill, the major change being considered after the Iran-contra affair, when covert arms sales to Iran were not reported to Congress for 10 months.

Webster took his most severe action against two of the more junior CIA officials involved in the affair, firing Tomas Castillo, the former Costa Rican station chief; and the former CIA base chief in Honduras, who used the name "Atkins."

Castillo assisted former National Security Council aide Lt. Col. Oliver L. North in resupplying the Nicaraguan contras in 1985-86 in violation of CIA policy and legal guidance. Castillo was one of the officials not "cooperative" or "candid" with the agency's internal inspector general during the initial investigation, according to an agency official.

"Atkins" supervised delivery of military equipment to the contras using CIA helicopters and also misled the inspector general.

Both dismissed men will receive federal retirement pay, an agency official said.

Webster removed Duane R. (Dewey) Clarridge as head of counterterrorist operations, demoted him one pay grade and gave him a letter of reprimand. Clarridge ran the contra operation during 1981-84 for Director William J. Casey. He assisted North in one of the early Iran arms shipment in November 1985, before a presidential "finding," or authorization, had been issued. Although his CIA office was a command post for the delivery, Clarridge claimed he was not aware that the supply flight to Iran was carrying weapons. He is eligible for retirement.

Alan D. Fiers, who ran the contra-resupply operation as head of the Central American Task Force, received what a source called a "serious reprimand" for remaining silent while superiors misled a congressional committee last year about the operation. One source said Fiers was not demoted because of "his otherwise exemplary" record. Fiers will given a less visible job, the source said.

Webster's statement also said "five agency employes were not cooperative with or were not candid" with the CIA inspector general's internal probe. One source said three who work in Latin America received letters of reprimand.

Webster said that while "agency officers heard references to a possible diversion of funds to the contras as early as January 1986," these and other clues were deemed "implausible" and "the evidence was not so strong that anyone concluded a diversion had occurred."

During Congress' Iran-contra hearings, there was much criticism of the seven laws providing, modifying and then prohibiting aid to the contras over six years. But Webster said CIA headquarters was able to sort through the laws and provide guidance to the field that "was generally clear and often more conservative than required."

Webster portrayed his personnel decisions as a purely internal corrective action taken independently.