To have 13 bosses as different and demanding as the members of the D.C. City Council is hard enough. But most afternoons, around quitting time, Bob Williams gets a phone call from the toughest boss of all.

His mother.

"She always asks me, 'Son, what have you done wrong today?'" said Williams.'But more and more, in the last couple of years, I am able to tell her: 'Nothing, mama.'"

Where confusion and inefficiency were frequent when the elected City Council first took office, Williams thinks matters have improved. The reasons, he says, are experience and a few administrative reforms. The real reason, say council employes and members, may be Robert A. Williams himself.

Ever since limited home rule came to the District of Columbia in January 1975, Williams has been secretary to the City Council. His job description says he is the council's chief administrator. But his role is part choreographer, part center fielder, part snake charmer.

He administers the council's public service programs and supervises the staff of 22 that keeps council business running. He handles questions from the public and projects for the council. He supervises the work of 11 committees. He is responsible for everything from compiling legislative histories to ordering light bulbs.

"All dollars, all invoices, all paper, every piece of legislation flows through this shop," said Williams. "But service is what we're all about - administratively, to the council and to the public."

When Williams first took office, "everything was terrible. These were all newly elected people. They'd never been bureaucrafts before."

When he leaves this coiming January to "go back to being a capitalist," the council, he thinks, will "be running smoother than it's ever been."

A 51-year-old career school administrator and manpower consultant, Williams styles himself a nonbureaucraft in a job that would seem to demand the opposite.

He dials his own phone calls. He sometimes answers his secretary's phone. According to his assistant, Patricia Miner, he never loses his temper. He may be the only District government employe never to have hung pictures on his office wall for fear of getting complacent.

But he gets high marks from council members. Six were asked to summarize William's performance. All used the word "professional." None found anything negative to say.

That may be a window on how well Williams has picked his way among the personalities and factions on the council.

He is a longtime friend of Council Chairman Sterling Tucker, who brought Williams onto the council staff. But Williams says he has been careful never to appear like "Tucker's mans," or do more for Tucker than for other members.

"Tucker hasn't asked me to do a thing that could be misunderstood," Williams said.

But other members have.

A member once asked him to prepare hundreds of copies of a mailing. Williams thought the material was partisan and personal, and refused. The member, whom Williams would not identify, backed down, and Williams said he has had no such requests since.

"The members of the council are really pretty responsible people," said Williams. "They don't want to misuse and funds. They don't want an audit over a $5 parking ticket."

Williams acknowledged that Washington's city government has come under considerable criticism. "But most of it was of the executive," he said.

Williams refused his job when it first offered to him five years ago. He accepted the second time around, he said, "to show that black people can run a government well.

"You can't change much, "Williams said. "But at the very least you can avoid keeping people who call up on hold for more than a minure. We've tried to translate to people that there is a way to get something done in government."

Williams, a GS-16, is one of the two highest-paid staff members on the council. He makes $42,400 a year (council members earn $28,444). But like all staffers, he serves at the council's pleasure.

"There aren't any politicans in this office. Just good, solid people," he said. "You couldn't pay any of us to run!"

Born in Detroit, Williams moved here with his family when he was 5. He is married and the father of three children - a daughter who works for the District government, another who attends Georgetown University and a son in high school. He graduated from Dunbar High School, and holds a BA degree from the former Miner Teachers College (which later became D.C. Teachers College) and a master's degree from New York University.

A veteran of 15 years of administrative wars with the D.C. public schools, Williams said he spends the greatest amount of his time preparing the council agenda, handling requests from the public and keeping records. His office produces an average of 80,000 pages of printed matter a month. But Williams said his greatest headaches spring from the "little things."

For example, even though Tucker and Mayor Walter E. Washington decide who gets them, it is up to Williams to assign low-number license plates and to keep track of who gets which.

"Let's say Willie Hardy, who represents Ward 7, wanted tag number 777, and someone else had it already," Williams said. "That can be trouble."

Similarly, Williams' office is the "storage office" for the records of the city's Advisory Neighborhood Commissions (ANCs). Each has its own elected officials, agenda and bylaws. It hasn't happened, but if Williams made a mistake in any ANC recordkeeping, "I might make an unnecessary enemy on the council."

Williams might well be offered a toplevel job in the executive branch if Sterling Tucker is elected mayor this fall. But he says he would decline it.

"If I were going to stay in government, I'd stay right here," he said. "But I want to go back to private industry (as a consultant). You can't stay in this job forever, and most of the machinery is in place now."