View cart

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description usefully adds what the response contains (lines, quantities, total), but says nothing about empty-cart behavior, currency, or whether calling it recalculates totals.

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?

Extremely short and front-loaded, with the return contents stated immediately. The trailing Chinese phrase 查看购物车 is a pure duplicate of the English rather than added information, a minor waste of the limited budget.

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 zero-parameter read tool this is nearly sufficient, and the description does supply return-field information even though no output schema exists. It could go further on empty-cart behavior and its relationship to preview_order, but nothing essential for calling it correctly is missing.

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?

The tool takes zero parameters, which is the baseline-4 case; there is nothing for the description to disambiguate. Not specifying whether the cart is scoped to the current session is a small residual gap, but no parameter exists to control it.

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?

"Show cart lines, quantities and total" states a specific verb (show), the resource (cart), and what is returned, which distinguishes it from the mutating cart_add/cart_remove/cart_clear siblings. It stops short of explicitly contrasting with preview_order, which also surfaces totals, so an agent must infer the difference from the names.

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?

The description never says when to call this versus preview_order or order_status, nor mentions any prerequisites such as first calling select_store or cart_add. The read-only nature of viewing a cart is only implied by the word "Show".

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