An agent's test run becomes a regression asset only when someone writes the path down

Give an agent a goal and it chooses the route at run time. Tell it to check whether a user can create a project, and it will open the product, find a way into the flow, fill the form, handle a modal and look at the result ^[1]. When something unexpected happens, it reads the page, the source, the logs or the network traffic, then picks its next action ^[2]. That loop is why the first few minutes of testing a feature have changed ^[18].

Regression drives the same browser and wants something else from it. Its signal is the comparison between this run and the last one, which means the procedure has to hold still while the product moves ^[3]. The post is specific about how an uncaptured run drifts: the next one might enter through a shortcut instead of the sidebar, accept a success toast as proof, or inspect the list only sometimes ^[8]. When two of those vary at once, a red result has two candidate causes, and someone has to rerun by hand to separate them.

Three of the four things the post says go missing are written by a person before the run. The fourth is output the run has to emit ^[19]. The path is a named sequence with its preconditions: sign in as an administrator, create a project with unique data, save it, search for it, verify the status is Draft, and keep that sequence visible, reviewable and updated on purpose when product behaviour changes ^[10]. The checks become named assertions, because a pass with no assertion can mean only that the agent reached a plausible-looking page ^[11]. Agents can suggest those assertions ^[15]. Test data gets its own contract: many UI tests fail on the second run because they reuse a name such as Test Customer, depend on an expired session, or assume a prior approval is still pending, so the asset records how it reaches the state it needs and how it avoids collisions ^[12]. "This is not glamorous test work, but it is what makes a release check trustworthy," the author wrote ^[13].

Failure evidence is the fourth item. "The agent could not complete the task" is where diagnosis starts, and the next person needs the case, the step and what the page looked like at that point ^[14].

The post never makes the strong version of this argument, that an agent cannot produce comparable runs at all. The wording is conditional: unless the team deliberately captures the path and its checks, the next run may differ in meaningful ways ^[8]. If a team captures the plan, keeps the trace and replays the same steps in the same order, the agent is the authoring tool for an asset that a runner executes. The post reports no pass or flake rates and no comparison of an agent-driven suite against a recorded one ^[16].

The argument transfers to teams with two properties. The release gate has to depend on comparing one run against the next, and the person triaging a failure has to be someone other than the person who wrote the check. The post's own example assumes both, since the check has to work next week, during the next release, and when a different teammate is on call ^[7].