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

Annotations already declare readOnly, idempotent, non-open-world and non-destructive, so the safety profile is covered. The description adds genuinely useful context the annotations cannot: ordering ('oldest first') and the shape of results — platform subdomain always `active`, custom domains carrying verification status and outstanding DNS records. Only pagination/result-size behavior is unaddressed, which is minor given the single-parameter signature.

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 tight sentences with no waste: the first front-loads what is returned plus ordering, the second adds the only non-obvious detail (platform subdomain is always active; custom domains carry status and pending DNS records). Nothing is repeated from the schema or annotations.

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 read-only list tool with full annotation coverage and no output schema, the description supplies the return composition and ordering an agent needs. The only gaps are the semantics/format of `websiteId` and any result-size behavior, neither of which is likely to cause a wrong call.

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 single `websiteId` parameter has no documentation in the schema. The description implies the parameter identifies the target website ('attached to the website'), but adds no format guidance (opaque ID vs. slug) and does not state whether it must be an existing site, so it only partially compensates for the coverage gap.

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 verb and resource ('Returns every domain record attached to the website') and enumerates the contents (platform subdomain plus custom domains). It reads clearly as the list operation among mutating websiteDomains_* siblings, though it never names or explicitly contrasts those siblings.

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?

There is no explicit when-to-use or when-not-to-use guidance and no named alternative (e.g., 'use before websiteDomains_verifyCustomDomain or websiteDomains_setPrimaryDomain to obtain the domain identifier'). Usage is only inferable from the tool name and from the fact that it is the only read operation in the domain group.

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