What a Human Chief of Staff Does

Before you set up an AI version, get clear on the human one. A chief of staff is a senior aide whose job is to make one leader, the principal (usually the CEO), as effective as possible.

The clearest public picture of the job comes from McKinsey. It ran forums with more than 200 chiefs of staff over five years, published an article on the role in 2023, and released a podcast in 2024 with senior partner Andrew Goodman. In their description, the scope runs from administrative to strategic. It depends on the organization and on the relationship between the two people.

HBR's 2020 article "The Case for a Chief of Staff" by Dan Ciampa starts from one premise: CEOs need more support than an executive assistant can give. Only the summary is public, so treat it as support for that premise and nothing more.

Here is the gap in practice. Your assistant can find a slot for Monday's leadership meeting. Nobody makes sure you walk in knowing that sales and operations count capacity differently on the national-chain contract. That second job belongs to a chief of staff.

McKinsey describes three duties that fill most of a chief of staff's day.

Information and paper flow. The chief of staff prepares and filters what reaches you, including board presentations and the inputs to key decisions. You see what matters, in a form you can use.

Air traffic control. Andrew Goodman's own phrase. The chief of staff manages your workflow and keeps track of actions and activities, so nothing collides or circles forever.

Meeting preparation and the record. The chief of staff joins meetings so you arrive prepared, and keeps a record of what was said and agreed.

Take a week with the national-chain contract on the agenda. Information flow means one page on the contract terms, the margin and the capacity gap, in place of forty emails. Air traffic control means the finance review doesn't land after the board chair's Friday deadline. The record means that when someone says "we agreed to phase it in," a note shows who agreed and when.

Flip the cards to test yourself on each duty.

Two more duties are about time and visibility.

Peripheral vision. The chief of staff acts as your eyes and ears so there are no surprises. McKinsey notes that senior leaders tend to bring the boss only good news. A good chief of staff also tells you what is happening on the front line. If the plant manager says privately that the second shift can't be hired in time, you need to hear it before the operating review shows a green status.

Calendar against the business cycle. The chief of staff lines up your travel and personal time with the planning, executive committee and board cycles. McKinsey suggests setting time aside, weekly if not daily, to scan the horizon and prepare for important events. In practice that means spotting that a two-week trip lands in the middle of board pre-read preparation and raising it a month ahead, not three days before.

Both duties protect you from the same thing: finding out too late.

A chief of staff also guards your priorities. One chief of staff in McKinsey's forum kept the principal to five or six, split into outward-facing (customers, the board, the market) and inward-facing (people, systems, operations).

Another kept a three-column list: now, soon and never. The never column records things that came up but will not be done. The point is that they get written down, not forgotten. When someone raises the idea again in three months, the list shows it was considered and set aside, and why.

Say a director suggests opening a second warehouse during the chain-contract discussion. You decide against it for now. Without a never column, the idea either nags at you or quietly comes back as if it were new. With one, it is recorded as raised and not pursued.

Match each item to where it belongs.

Commitments made in meetings drift. Follow-through is the duty that stops this. The chief of staff tracks what was agreed, by whom and by when, and checks that it happened.

McKinsey adds a related duty for transitions. When the chief of staff moves on, they write a handover plan that documents key past decisions. Whoever comes next can then see what was decided and why, without reconstructing every conversation.

Here is how it runs with the second-shift hire. In Monday's meeting the COO says recruiting will start by the 15th. The chief of staff writes that down with the date and the source. On the 12th they check progress. On the 16th they see it has slipped and bring it to you, so you can decide whether it needs a conversation. Six months later, the decision record shows why the phased start was chosen.

Put the steps in order.

Now apply the list to yourself. Open your calendar and sent mail for last week. Write down eight to ten things you or your assistant spent time on that were not the decisions themselves. Tag each with one duty:

• Information flow
• Air traffic control
• Meeting prep and the record
• Peripheral vision
• Calendar against the business cycle
• Priorities (now, soon, never)
• Follow-through and handover

Most CEOs find the same pattern. Plenty of time goes to reading long threads (information flow) and chasing what was agreed (follow-through), and little goes to deliberate horizon scanning. Some tasks won't fit any duty, and that tells you something too.

Keep the list. In later lessons it becomes the starting point for what you hand to an AI and what you keep.

Try the match first, then tag your own list.

The boundaries matter as much as the duties. McKinsey names five.

1. Does not decide for the principal. Scope and decision rights should be agreed explicitly up front and revisited as the role evolves.
2. Does not blur whose voice it is. People respond to a chief of staff because of borrowed halo authority: the weight that comes from being close to the boss. A good one is clear about when they speak for themselves and when they speak for you.
3. Does not play politics. It sits on the leadership team but stays independent of it.
4. Does not isolate the principal. Guarding your time is part of the job, but the CEO's office should not become an island.
5. Does not make itself the story. One chief of staff in McKinsey's article said the job is to make the principal look good, not yourself.

Imagine the head of sales gets a note saying "we're leaning toward signing." If they can't tell whether that's your view or your aide's guess, halo authority has been misused. Keep these five in mind. Each one has an AI equivalent, which the next lesson covers.