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

With only readOnlyHint=false provided, the description carries most of the behavioral burden; it does disclose a genuinely important side effect — passing floor_price=null cancels auto-deal and routes all bids to the seller's AI. It does not say whether this is a partial update (unmentioned fields preserved), what permissions manage_url confers, or whether changes are reversible.

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 short sentences with the purpose front-loaded and the single most non-obvious semantic rule (floor_price=null) immediately after. No filler.

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 an eight-parameter mutation tool with near-zero schema coverage, no output schema, and only a readOnlyHint, the description leaves too much unspecified: partial-vs-full update behavior, the meaning of manage_url as an authorization handle, and the semantics of the remaining fields are all absent.

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 13%, so the description must compensate, yet it only explains floor_price's null semantics — valuable added meaning beyond the schema's integer|null type. The other seven parameters (price, title, location, quantity, condition, description, manage_url) get no explanation in either the schema or the description.

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?

「修改商品欄位」states a specific verb (modify) and resource (listing fields), so an agent knows this is an update operation on a listing. However, it does not distinguish itself from siblings such as listing_action, create_listing, or get_listing, so the agent must infer the boundary.

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 guidance on when to use update_listing versus listing_action, create_listing, or get_listing, and no preconditions (e.g. that manage_url is required and how to obtain it). The only conditional behavior mentioned concerns floor_price=null, not tool selection.

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