Get a Chinese car

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: it discloses that the tool resolves cross-marketplace duplicates ('same car on the other marketplace') and surfaces export status, which an agent could not learn from the schema alone. It does not cover freshness/auth/rate-limit behavior.

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 front-loaded sentence with a colon-delimited list of what the record contains; every clause carries information and nothing is redundant.

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?

With no output schema and only two well-documented params, the description appropriately compensates by enumerating the returned fields (price history, photos, seller, export status, cross-marketplace match). Complete enough for an agent to call it correctly, though it could clarify the relationship to its search sibling.

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 both parameters are already documented, establishing a baseline of 3. The phrase 'same car on the other marketplace' loosely justifies the optional `source` param, but adds little beyond what the schema's own enum description (needed when an id exists on both) already states.

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 ('Full record for one Chinese listing') and enumerates the record's contents, which clearly implies single-listing retrieval as opposed to the sibling search_chinese_cars. It does not explicitly name the sibling it differs from, so it falls just short of 5.

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?

No explicit when-to-use or when-not-to-use statement, and no named alternatives. Usage is only implied by the schema's hint that the id comes from search_chinese_cars, leaving the agent to infer the search-then-fetch workflow.

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