Why working with AI agents is so tiring (and what to do about it)

Earlier this week, I spent five hours at the WERK1 coworking space in Munich, moving three projects forward at once: the brain dump that would become this blog post, a contribution to an open source project, and a redesign of my blog’s analytics. My AI agents did the heavy lifting. Whenever one of them finished a work package, I reviewed the results, made a few decisions, wrote the next set of instructions, and hopped over to the next project. It felt great: three streams of steady progress, one me.

Then I came home for dinner and noticed that my head was buzzing. I know this particular kind of tiredness well, but from a different life: it’s how I used to feel after a day of back-to-back job interviews or customer workshops. This time, I had spent the day mostly alone, typing.

Wait, isn’t this multitasking?

At the surface level, what I did that day was an anti-pattern: I hopped between tasks all afternoon (I’ve started calling it agent hopping), and in productivity circles, multitasking is supposed to be a lie we tell ourselves. Paul Graham wrote in one of my favourite blog posts of all time that makers and managers live on different schedules, and that a single meeting interrupting a long work session can ruin a maker’s afternoon. Cal Newport built a whole body of work around deep, uninterrupted focus. Psychologists have measured again and again that task switching degrades our performance far beyond the seconds the switch itself takes.

And yet, the people building the newest AI tools work exactly this way, all day. Fiona Fung, who manages the Claude Code and Cowork teams at Anthropic, cheerfully described on Lenny’s Podcast how she kicks off multiple agents at once, and knits through meetings while they work.

Either decades of research are wrong, or this isn’t multitasking.

You’ve been promoted to head chef

I think “agent hopping” (if this is a word) is not multitasking. And the best picture I’ve found for it comes from Gene Kim and Steve Yegge’s book Vibe Coding. Working with AI agents, they say, is like running a professional kitchen: you are the head chef, and the agents are your line cooks. You don’t chop the onions yourself anymore. You write a ticket, hand it to a cook, and turn to the next dish. The switching happens at the hand-off, the natural seam between tasks, not in the middle of a thought.

There’s a second difference that I think matters even more: you choose the moment. Sophie Leroy, the researcher who discovered that part of our attention stays stuck on an unfinished task after we switch away from it, found the effect is at its worst when we’re forced to switch under time pressure. A ringing phone yanks you out. An agent that finished its work waits patiently until you’re ready. The seams are self-timed.

I’ve seen a similar effect in my computer systems work before: in the mid-2000s at Sun Microsystems, I helped introduce servers that swapped one very fast processor for many slower ones working in parallel. In kitchen terms, we asked our customers to trade one brilliant, expensive chef for a whole brigade of decent cooks, and most of their software simply wasn’t organized to work as a brigade yet, so it was a hard sell. Today’s AI brigade shows up pre-trained. It even speaks English, and most other languages, too.

So no, working with agents isn’t multitasking in the classic, self-deceiving sense. It’s running a kitchen. Which leaves the question: why the buzzing head?

The kitchen in your head has no ticket rail

Because the kitchen picture breaks in two places, and the tiredness lives exactly in the breaks.

A real kitchen keeps its state out in the open: the orders hang on a ticket rail above the pass, and the chef’s head can stay comparatively empty. Your brain has no such rail. Psychologists have known since the 1920s that unfinished tasks keep occupying our minds, and that we can only actively track about three or four things at a time. Every dish that’s still cooking with an agent somewhere keeps simmering in your head, too.

And here’s the subtle part: handing off a ticket doesn’t finish anything. The dish is still yours until you’ve tasted it and sent it out. Delegating to an agent softens the cost of switching. It doesn’t clear the plate.

The cooks took the chopping

The second break is sneakier. The line cooks didn’t take a random part of your work. They took the easy part.

Drafting routine code and text, summarizing documents, doing research legwork: that used to be the lighter part of a working day, the part where your mind could coast a little. What tends to remain for you (tends, because there’s still plenty of mindless cleanup in AI land) is tasting and deciding: reviewing results, making judgment calls, working on strategy and direction. As Steve Yegge put it: “AI has turned us all into Jeff Bezos, by automating the easy work, and leaving us with all the difficult decisions.” And decision work is the most expensive kind of thinking we do. The best evidence I know of suggests we can sustain roughly four good hours of it per day; Yegge, after months of intense agent work, arrived at three to four hours as the realistic workday, too.

Agent work packs those hours tight. Every wait invites filling, so the pauses that used to come free with the work, like a coffee break while the computer executed a long program, get filled with yet another round of deciding. That’s how a quiet maker day can feel like an interview marathon day.

You’re not imagining it

A more sensationalistic blogger would call this an “AI fatigue epidemic”, and they wouldn’t be wrong:

Simon Willison, a developer with decades of experience, describes it like this: “Using coding agents well is taking every inch of my 25 years of experience as a software engineer, and it is mentally exhausting. I can fire up four agents in parallel and have them work on four different problems. And by like 11 AM, I am wiped out for the day.”

A field study of 200 tech workers found the same pattern and called it work intensification: “a continual switching of attention” and “a sense of always juggling.”

Laura Summers at Pydantic, who call themselves an “end-to-end AI engineering stack”, writes: “Programming with LLMs is genuinely useful and genuinely destabilizing. These two things coexist. If we pretend the second one isn’t happening, we will all burn out.” She also offers hope by pointing out that “It was always the human attention, the engineering judgment, the ability to hold a coherent vision for a system. … those human capacities are revealed as the actual scarce resource. And scarce resources are valuable.“

Speaking of burnout: in this year’s tech worker sentiment survey, significant burnout jumped from 44.7% to 54.7% in a single year. Agent fatigue is at most one contributor among many there (layoffs and job insecurity surely do their part), but the direction is worrying.

Even Fiona Fung, when Lenny asked her how to handle the growing context-switching load, answered: “I haven’t cracked it yet.”

What I do about it

I don’t claim to have cracked it either. But the following practices have made my agent days noticeably lighter, so take them as field notes rather than final answers.

Expect the tiredness. It’s arithmetic, not weakness. If you delegate the light work, what remains for you is dense by definition. I stopped being surprised by the buzzing head and started accepting it, the way a chef plans for the dinner rush: it’s coming, so don’t schedule anything deep behind it.

Build yourself a ticket rail. I write long, careful briefs for my agents, something I’ve described in How to stop engineering prompts and start delegating. A good brief does two jobs at once: it makes the agent better, and it takes the dish out of your head. Leroy’s research offers the same remedy for humans, a short written note on where you stopped and what happens next, so your mind can let go. Then take your break at the hand-off, not at random: after I send off a brief, I stand up, stretch, make coffee, play a move on Chess.com, or send my wife a message. Five minutes is enough. And check on your cooks on your schedule, not theirs: peeking at a still-working agent is a paid interruption with zero yield, and agent notifications that interrupt you rebuild the bad kind of task switching with extra steps. (Though I do find Peon Ping hilarious.)

Cap your burners. One big dish, at most two small ones on the side. My personal Kanban board enforces this limit, and my brain is grateful for it. Some days, the right number of works-in-progress is one. Above all, enjoy the light work without guilt: the lunch walk, the small tool tinkering between hand-offs. The silly pet project. Fiona Fung knits, and I think that’s the perfect extreme case: a task that occupies the hands and costs no working memory at all.

After hours: give yourself permission to play. My mother used to work as a diplomat in the German foreign ministry. Our family spent many years in foreign countries she was assigned to: Colombia, Turkey, Italy, Portugal, Spain. As I grew older, she told me about her colleagues who used Valium and alcohol after an intensive day at the office to wind down. At the time, I had introduced her to computer games and she loved playing Pac Man, Krakout, and, of course, Tetris. She told me that this was her wind down ritual, no drugs required. Today, I love playing The Legend of Zelda: Breath of the Wild. I recently saw it ranking high on a list of “best cozy games”. “Wait!” I thought to myself, “Zelda, a cozy game?” But, yes, it makes sense. There’s a lot of meditative comfort in exploring the vast world of Zelda at your own pace, collecting stuff, completing quests, and relaxing in a beautifully made imaginary world.

Stay awake at the wheel

I wrote a few weeks ago that we’re in the driver’s seat with AI, if we choose to stay awake. Agent fatigue is exactly where that choice gets hard, because the real risk isn’t being tired. It’s what tired brains do: accept the agent’s recommendation without thinking it through, skim the review that deserved attention, let the evening reading collapse from books into feeds. You can frequently find me reading a good non-fiction book on my morning commute, but my evening commute is more often spent on Reddit.

Air traffic controllers and truck drivers get mandated rest, because as a society, we’ve learned the hard way what vigilance fatigue does in those professions. Nobody is going to mandate rest for people running AI agents; all we get is a smartwatch reminding us to stand up. So this one is up to you: see the arithmetic of doing more executive work than ever before. Congratulate yourself on your promotion to head chef. Build the rail. Cap the burners. And step away from the pass while the cooks are cooking.

So, tell me: what’s on your burners right now, and what’s your knitting?