list_custom_hostnames

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

With no annotations, the description carries the full burden; it does reveal that this is a read-only list operation scoped to a zone. It does not mention pagination behavior, response shape, or how filters interact, which makes it minimally adequate but not richly transparent.

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?

A single sentence with no filler; the action, resource, and scope are front-loaded. Every word contributes to understanding what the tool does.

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 zone-scoped list tool, the description plus a fully documented parameter schema is sufficient to invoke correctly: provide zone_id and optionally hostname and per_page. It omits an explicit return-shape statement, but there is no output schema and 'List' strongly implies a paginated array of custom hostnames.

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 100%, so the required zone_id plus optional hostname and per_page parameters are already documented. The description's 'for a zone' aligns with zone_id but adds no new meaning about filtering or pagination defaults, so the baseline score of 3 applies.

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?

States the specific verb 'List' and the exact resource 'custom hostnames (SSL for SaaS)' with scope 'for a zone.' The parenthetical clarifies what custom hostnames are and helps distinguish this from the sibling list_custom_certificates tool.

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 phrase 'for a zone' gives clear context that this is a zone-scoped enumeration operation. However, it does not name alternatives such as get_custom_hostname for a single hostname or list_custom_certificates for certificates, nor does it state when not to use this tool, so the guidance is implied rather than explicit.

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