nameserver_list

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

No annotations are provided, so the description carries the disclosure burden. The explicit 'Read-only' statement is useful and communicates that this is a non-mutating operation. But the description does not cover return format, pagination, auth expectations, or the effect of the optional domain parameter.

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?

Two compact sentences with no filler. The first states the action and read-only nature; the second gives a practical exclusion. Every sentence earns its place.

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?

For a simple one-parameter read-only list tool, this is adequate: the core action and a key scope limitation are clear. The main gap is the completely undocumented 'domain' parameter, and the absence of any statement about what is returned. An agent could call it correctly but might not know how to use the optional filter.

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?

Schema description coverage is 0%, and the description does not mention the optional 'domain' parameter at all. The property name hints at filtering by domain, but the tool text adds no meaning to the schema. With low coverage, the description needed to compensate and did not.

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 states a specific operation ('List DNS zones hosted on INWX nameservers') and adds a relevant scope exclusion for Cloudflare-hosted DNS. It is clear about what the tool does, though it does not explicitly name a sibling tool to distinguish itself from.

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 gives one clear when-not condition: it is not needed for domains whose DNS lives at Cloudflare. However, it does not name an alternative tool or explicitly state when to prefer this over nameserver_info or domain_list. Usage guidance is present but mostly implicit.

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