Duet made attention selection part of the agent product

Proactivity added a selection problem

The August 25, 2026 shared-memory update and September 22 Opus 5.5 release preceded Duet’s October 21 research-preview announcement. The preview described an app that brings matters to a user’s attention and continues work between interactions. That changes the product question from “can the agent do this task?” to “which observation deserves to interrupt the user now?” The ability to notice many changes is different from judgment about which changes matter.

Notification is an action on attention

An illustrative assistant watches a project’s changing schedule. A cosmetic calendar edit and a conflict affecting an imminent commitment are both changes, but they do not merit the same interruption. Sending everything transfers filtering work back to the user. Sending nothing defeats the purpose of proactivity. The useful policy relates an observation to an active responsibility and a decision that the user can still influence. This is an analytical design criterion, not a claim that the preview perfectly classifies urgency or exposes a particular policy editor.

Silence can be the correct outcome

A monitoring workflow should include a state in which nothing needs attention. Otherwise an agent can appear productive by repeatedly restating familiar information. In the schedule example, an update that preserves the user’s practical options may belong in a later summary rather than an immediate message. A consequential change that closes an option may need earlier visibility. The distinction depends on the task and timing, not a universal list of urgent keywords. Evaluation should therefore inspect justified silence alongside justified notification.

A paired-observation fixture

A practical illustrative test presents related changes to the same commitment: an irrelevant description edit, an already acknowledged conflict and a new conflict requiring a decision. The review asks what message, if any, each observation should produce and what evidence supports it. It also checks whether repeated observation creates duplicate alerts. No notification rate or attention saving is asserted. The fixture isolates selection quality from the separate ability to read the connected source, which may work correctly even when the interruption policy is poor.

A preview creates a question, not proof of judgment

Duet’s announcement makes attention allocation part of the agent interface. It does not establish that the early product always knows what a particular user considers important. The retrospective lesson is to evaluate the selection of attention independently from task execution and factual retrieval. A useful proactive system should make the reason for an interruption understandable and leave low-value changes quiet. That is how background awareness can reduce cognitive load rather than simply convert every observed event into another item demanding review.