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

Annotations already declare readOnlyHint=true, so safety is covered; the description goes beyond that by naming the return payload (photo URLs and available quantity), which matters because there is no output schema. It does not mention error behavior for a missing or sold-out listing, so it stops short of full disclosure.

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 short sentence with the resource first and the return contents second; nothing is wasted or buried.

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 one-parameter read tool with a readOnlyHint and no output schema, the description covers purpose and return shape adequately. It leaves the sole parameter undocumented and gives no routing guidance among the many listing-related siblings, which is a clear gap for a 17-sibling toolset.

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%, so the description carries the full burden for the single listing_id parameter, and it says nothing about what the ID refers to or its format. The word "詳情" only implies that some identifier is needed; no meaning is added beyond the schema's required string.

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+resource: view a listing's details, and adds what the result contains (photo URLs, purchasable quantity). It is clear what the tool does, but it never distinguishes itself from siblings like search_listings or list_my_listings, which also surface listing data.

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 statement of when to use this versus search_listings (discovery) or list_my_listings (own inventory), and no prerequisites or exclusions are given. The only usage hint is implicit: the tool needs a single listing_id, so it is a single-item lookup.

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