拼多多加购（受控写）

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is partly covered. The description adds real behavioral context beyond that: it only clicks explicit add-to-cart entries, it verifies the cart increment afterwards as an acceptance check, and it explicitly treats page/seller text as data rather than authorization — a meaningful prompt-injection guard for an open-world write.

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?

Three compact clauses with the most important constraint ('默认关闭的受控加购') front-loaded, followed by requirements, then execution and safety rules. Every sentence carries distinct information; only the injection-safety clause could be seen as tangential, but it earns its place for a write tool.

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 not be described, and annotations cover the read/write and idempotency profile. The remaining gaps are minor: what happens when the acceptance gate fails, whether a prior login is required, and how spec_selection is resolved against the live spec table are not addressed.

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 high (83%), so the schema already documents confirm, goods_id, sku_index and request_id, which sets the baseline at 3. The description reinforces the gating role of confirm and request_id and adds the constraint that the spec must map uniquely, but it adds no format, syntax, or default details for quantity, spec_selection, or sku_index.

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?

The description names a specific verb and resource (加购/add-to-cart on Pinduoduo) and qualifies it as a controlled write that is disabled by default. It is clearly distinguishable from the sibling read tool pdd_read_cart, though it never names that sibling explicitly to make the contrast airtight.

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?

It states concrete preconditions for invocation: confirm, request_id, a uniquely mapped spec, and an acceptance gate must all be satisfied. What it does not say is which sibling to call first (e.g. pdd_read_sku to obtain the spec table, or pdd_login for auth), so the routing guidance is implied rather than spelled out.

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