list_domains

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

With no annotations, the description carries the burden of explaining behavior, and it does: it is a read-only listing operation that returns specific details per subdomain. It does not mention pagination, rate limits, or authorization, but the lack of parameters and clear return scope make it a transparent description.

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 entire description is a single, information-dense sentence with no filler. It front-loads the main action and then lists the exact attributes returned for each subdomain, making it easy for an agent to quickly parse and use.

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?

Given zero parameters, no output schema, and no annotations, the description provides enough information to successfully invoke the tool and interpret the response. There is no hidden behavior or missing prerequisite that would prevent an agent from using this tool effectively.

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 input schema has zero parameters, so there are no parameter semantics to clarify. The description also tells the agent what the output contains, which is the only meaningful semantic information. A score of 4 is appropriate for a zero-parameter tool.

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 starts with the action 'List every subdomain on this account' and precisely specifies the scope: account-wide. It also states exactly what is included per domain: DNS records, and status flags for forwarding, proxying, or delegated nameservers. This makes it easy to distinguish from the sibling domain-specific tools.

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 account-wide scope and 'list every subdomain' language makes it clear that this is the enumeration tool for a domain overview, rather than a single-domain lookup or mutation tool. It does not explicitly name alternative tools or when-not-to-use conditions, but for a zero-parameter listing operation, the context is sufficiently clear.

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