读取拼多多商品详情（只读）

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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower; the description still adds real behavior: the item is reached by a real search-and-click path rather than by opening the URL, and page/customer-service text must be treated as data, not instructions (a useful injection warning). It does not cover failure modes, rate limits, or session prerequisites beyond 'same connection'.

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?

Front-loaded with the core workflow and read-only claim, then the price caveat and the injection warning. Dense and mostly waste-free, though it packs three unrelated concerns (navigation, pricing, prompt-injection) into one flowing block without separators.

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?

An output schema exists, so return values need no explanation; the description still covers navigation method, the price-assessment caveat, and the untrusted-content rule, which is what an agent needs to call this correctly. Missing only explicit guidance on when to prefer it over the sibling SKU/search tools.

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 coverage is 100%, so the baseline is 3; the description goes further by explaining what budget_max means in practice – when the displayed price is not bound to a specific SKU, price_assessment.reference_price is null and must not be treated as a confirmed final price. That adds decision-relevant meaning beyond the schema text.

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 concrete verb and resource ('读取…商品详情', 'read item detail') and makes clear the input URL is only an identifier, not something fetched directly, which separates it from a naive link opener. It never names the adjacent tools (pdd_read_sku, pdd_search) by name, so sibling differentiation is implied rather than explicit.

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?

Gives a concrete procedure – search inside the same session first, then click the single matching product card – and an exclusion ('链接…不直接打开'), so the intended flow is inferable. However, it never says when to choose this over pdd_read_sku or pdd_search, and no failure/stop condition beyond the entry parameter note is stated.

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