Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare read-only, idempotent, closed-world, non-destructive behavior. The description adds substantial domain behavior beyond that: caps and stage bounds are enforced on save, while capacities, locked regions, and per-region/per-engine caps matter only at launch and never block a save. It also explains the trial-specific locked entry behavior and the peak-bot limit.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with purpose and the id constraint, then proceeds through engine types and enforcement timing. It is dense and every sentence contributes domain-critical information, though it is longer than strictly necessary for a list tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema and no parameters, the description carries the burden of explaining what is returned and how it is used. It describes entry ids, the three engine types, locked behavior, and limit fields, which is substantial. It does not fully enumerate the response shape, leaving a small gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so the baseline is 4. There are no parameters requiring semantic clarification, and the description does not need to explain schema details.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'List everywhere a population can run.' It then defines what an engine is by classifying CLOUD, WILDCARD, and PRIVATE, and states the critical role of the entry id. This gives an agent a clear, differentiated understanding of the tool beyond the bare name.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description supplies clear usage context: never invent an id, use the entry's id as a population's engineId, and for free-trial customers place populations on an entry with locked false. It does not explicitly name alternative sibling tools or when not to call this one, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.