Agent teammate
An agent addressed as a participant on a shared board rather than invoked per prompt: it takes items, reports into them and hands them back.
An agent teammate is configured once and then works from a shared queue, rather than being summoned by a prompt each time. It has a persistent identity colleagues recognise, its own model, instructions, tool access and permissions, and it reports progress into the item it is working rather than into one person's private session.
The practical difference is addressability. A prompt-invoked assistant exists inside the session that started it; an agent teammate appears where the humans already are, can be handed an item by someone who did not configure it, and leaves a trail attached to the work. Persistent, checked-in agent definitions are now common — Claude Code, Cursor and OpenCode all support them — so the dividing line is increasingly the surface the agent reports into, not whether it can be configured.
The term as used here is TODO for AI's. Microsoft's Work Trend Index describes the matching human role as an 'agent boss': a person directing several agents rather than operating one tool.