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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety bar is low. The description adds real behavioral context beyond that: it reads live inventory rather than a cache, performs no appraisal side effect, and each listing carries a fixed price, an appraisal range and a buy link. Rate limits and pagination ceilings are not disclosed.

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 tight sentences with the core action front-loaded and no filler. The middle sentence describing listing contents is slightly redundant given an output schema exists, but it is not wasteful enough to hurt readability.

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 9-parameter search tool with an output schema, the description covers what the tool returns and its read-only nature but leaves half the parameters undocumented. An agent can call it, but cannot confidently use price or sort parameters from the definition alone.

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 only 22%: q and tld are documented, but sort (7 enum values with no meaning), limit, offset, maxLength, acceptsOffers, minPriceCents and maxPriceCents are bare. The description says 'filter, sort and page' generically but adds no units, defaults, or interpretation for these parameters, so it fails to compensate 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?

States a specific verb (filter, sort, page) plus the exact resource: domains listed for sale by DNS-verified owners. It also draws one boundary against appraise_domain ('runs no appraisal'), but does not distinguish itself from the similarly named read_for_sale_dns / read_for_sale_page 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?

Usage is implied by 'reads the live inventory' and the 'runs no appraisal' caveat hints that appraise_domain is the tool for valuation. However, there is no explicit statement of when to choose this over search_recorded_sales or read_for_sale_page, so the agent must infer.

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