Cognitive Load
When you supervise several agents at once, the bottleneck stops being the machine and becomes your attention. This lens collects the three human-factors failure modes that show up most reliably in agentic work, and connects each to a signal the workspace toolkit already measures.
Three failure modes
Section titled “Three failure modes”Attention residue
Section titled “Attention residue”Switching between tasks leaves part of your attention stuck on the one you left — measurably degrading your judgment on the one you moved to (Leroy, 2009). Round-robining between concurrent agent sessions is high-frequency task-switching by design, so residue accumulates: your review of session B is worse because session A is still resolving in the back of your mind. The cost is on quality of judgment, not just time.
Vigilance decrement
Section titled “Vigilance decrement”Humans cannot sustain attention on a source that rarely needs them; effective monitoring degrades within tens of minutes (Bainbridge, 1983). “Watch every diff and step in when it’s wrong” is exactly this failure mode — the agent is competent 95% of the time, which lulls you into low vigilance right before the 5% that needs you. Passive monitoring is the wrong verification strategy for the same reason it fails pilots and plant operators.
Supervision fatigue
Section titled “Supervision fatigue”The compound cost of the two above, plus the shift Bainbridge described: automation removes the easy work and leaves the human the hard, intermittent, high-stakes judgments. Orchestrating agents is tiring in a way writing code is not because the residual job is dense with exactly those judgments, delivered on the agents’ schedule rather than yours.
The measurement surface
Section titled “The measurement surface”These failure modes are not just felt — the AIOS workspace toolkit instruments them. The analysis layer emits a set of attention (sanity) metrics from your own session activity, computed over active_hours (wall-clock time split into blocks at idle gaps):
| Metric | What it measures | Failure mode it proxies |
|---|---|---|
focus_block_avg_min | Mean length of an uninterrupted work block, in minutes | Flow conditions — short blocks mean an interrupt-shredded day |
context_switch_rate | Project changes between consecutive user prompts, per active hour | Attention residue from switching what you’re working on |
interrupts_per_hour | User prompts that hop to a different session, per active hour | Attention residue from switching which agent you’re supervising |
concurrent_sessions_peak | Max distinct sessions active in any 5-minute window | Supervision load — how many threads you held at once |
Why measure attention at all
Section titled “Why measure attention at all”Because the other AM axes protect code quality, and none of them protect the operator. Verification checks the work; context hygiene checks what the model sees; the autonomy axis checks how much you delegate. But a developer can be excellent on all of those and still be running so interrupt-shredded a day that their judgment — the thing every one of those axes ultimately depends on — is degraded.
Measuring attention makes the invisible cost visible, and gives you something to act on: fewer concurrent sessions, longer focus blocks, batched interruptions. The playbooks turn those levers into workflows.