When the Federal Reserve raised its discount rate by half a point on Friday, the central bank said, in a statement more cryptic than usual, that the step was taken "to deal effectively and in a timely way with potential inflationary pressures."

There was no mention of the declining U.S. dollar because Federal Reserve officials did not want financial market participants to think -- correctly or otherwise -- that the Fed had a particular value of the dollar that it planned to defend, and that the markets could use as a key to anticipating future Fed actions, sources said.

Nevertheless, the dollar's precarious position was a major factor in the decision to raise the discount rate from 5.5 percent to 6 percent. But so were plunging long-term bond prices, which have been hurt by rising expectations on the part of many traders of higher future inflation.

Last spring, when the dollar and long-term bond prices were falling together, the Fed made reserves less readily available to the nation's financial institutions. The tightening of credit conditions boosted some key short-term interest rates by about three-fourths of a percentage point. However, the demonstrated willingness to tighten helped contain inflationary expectations of market participants to the point that long-term interest rates declined by half a point or so.

If the Fed was hoping for a similar reaction this time, yesterday's market reaction was not encouraging. Both short-term and long-term rates rose in response to the increase in the discount rate -- the interest rate the Fed charges when it makes loans directly to financial institutions. For instance, 30-year federal government bond yields reached about 9 5/8 percent, up from less than 9 1/2 percent late last week and less than 9 percent two weeks ago.

Charles Lieberman, managing director of Manufacturers Hanover Securities Corp., questioned the wisdom of the Fed move. "I think they have gotten into a game that has limited degrees of freedom and that will have serious consequences," he said. "If they are trying to support the dollar, 50 basis points won't do it." A basis point is one-hundredth of a percentage point, so the half percentage point increase in the discount rate was a 50 basis point rise.

Further increases in rates, Lieberman said, would run the risk of damaging the U.S. economy to the point that it would risk a recession. At the same time, he added, there is little or no evidence that inflation is about to worsen, particularly since "labor costs continue to rise only slowly."

Some other analysts viewed the Fed action much more favorably depite the response of bond prices.

Scott E. Pardee, vice chairman of Yamaichi International (America) Inc., said the move "answered the question that traders were asking, 'what will the Fed do?', and more personalized, 'what will Alan Greenspan do?' " Greenspan took over as Fed chairman last month.

Pardee said higher short-term rates will make it more expensive for traders to speculate against the dollar while directly supporting the efforts of the Fed and other central banks that have been intervening in foreign exchange markets to support the value of the dollar. Pardee once handled such interventions for the Fed.

Among many bond traders, "inflationary expectations have taken deeper root" with the unemployment rate down to 6 percent, very close to the point at which, historically, inflation has begun to heat up, Pardee said. However, the economy is not overheating right now, he agreed.

Economists remain divided over future inflation, with some predicting that consumer prices will be rising at a 6 percent rate or more next year and others saying that inflation will be running in the 3 percent to 4 percent range.

The latest forecast from Data Resources Inc., for example, shows consumer prices increasing at less than 5 percent in the rest of this year and in 1988. Joel Popkin, who heads a Washington consulting firm, Joel Popkin and Co., is even more optimistic about prices in the short run, predicting a less than 4 percent increase over the next 12 months before tight labor markets begin to push wages, and therefore prices, up more rapidly.

But other economists think the economy is close to the point that most of its productive capacity is in use, and that further increases in orders for goods will trigger some rapid price increases.

In its Friday statement, the Fed noted "potential inflationary pressures" rather than actual pressures, so it was not taking sides in this forecasting debate, one analyst said. The point was to demonstrate a willingness to resist such pressures whenever they arise. Whether that signal will also bring down long-term interest rates a notch as they did last spring remains to be seen.