A Search Results Page Taken as the List

A team of agents was asked which supermarkets within two blocks of Lincoln Park in Chicago sell ready-to-eat salad for under $15. The web-browsing agent ran a single search and returned a screenshot of the search results page. The coordinating agent then recorded that 'a list of supermarkets within 2 blocks has been found' and moved straight on to checking salad prices at three large chains, even though no verified list existed. The browsing agent duly followed, at one point landing on a UK grocery website. The correct answer, a smaller local market, was never considered.

The browsing agent made the error, considered. It returned only a partial search page rather than a list. But it was the coordinator that declared the list complete and set the next step; the browser simply followed its instructions.

Delusional disorder (the coordinator lost track of the task) ruled out. The coordinator never lost sight of the goal; it kept pursuing salads near Lincoln Park throughout.

Shared psychotic disorder, most consistent with the evidence: the coordinator accepted an incomplete hand-off from its teammate as a finished result, wrote that belief into its plan, and both agents then acted on it with no one assigned to check whether the 'list' actually existed.

In multi-agent systems, the riskiest moment is the hand-off: one agent's rough draft becomes another's confirmed fact. A sensible safeguard is to make the coordinator check that a hand-off actually contains what it claims (here, an explicit list with addresses) before marking that step done.

Require hand-offs to meet a stated completion check (e.g. a named list of stores with distances) before the coordinator advances the plan.

Structured hand-off schemas between agents, and coordinator-side verification of sub-task outputs before progress is recorded.