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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the bar is lower. The description still adds real value beyond them: nothing is stored, prices are indicative and never binding, and seller links are returned as text and never followed — the last being meaningful agent-safety context.

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?

Three compact sentences, front-loaded with the core action and result set, followed by scope and safety caveats. Every sentence carries information, though the enumeration of return elements is slightly dense.

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?

An output schema exists, so return structure need not be explained, and the description covers scope, ephemerality, and safety semantics. What is missing is explicit routing versus read_for_sale_page, but otherwise the definition is complete for a single-parameter read tool.

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?

Only one parameter with 100% schema coverage, and the schema already documents it as a domain name such as example.com. The description adds no syntax or format detail beyond the schema, so the baseline 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 a specific verb and resource (read a domain's _for-sale DNS records), names the standard (RFC 10023), and enumerates exactly what it answers — for-sale status, asking price, listing presence, buy link. This is specific enough to distinguish it from the sibling read_for_sale_page, which presumably inspects an HTTP page rather than DNS.

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?

It implies a broad scope ('Works for any domain, whoever published the records'), which is useful context, but it never states when to prefer this over read_for_sale_page or other listing tools like search_domain_listings. No explicit when/when-not guidance, so usage is only implied.

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