浏览拼多多首页/分类（只读）

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

The annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is largely covered; '只读' merely restates it. The genuinely additive part is the prompt-injection warning that page and customer-service text is data only and never authorization or an execution instruction — a real behavioral constraint an agent would not otherwise know. Gaps remain around login state, pagination/scroll behavior, and how many cards are returned per page.

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 short clauses, front-loaded with the action and resource, then the read-only note, then the injection guard — no filler. The redundant '只读' against readOnlyHint=true is the only wasted clause, and it is negligible.

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, and the tool is low-complexity with one optional parameter. However, the description omits the login prerequisite implied by the pdd_login sibling and gives no hint about `limit`, leaving an agent to guess at invocation context.

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 single `limit` parameter has 0% schema description coverage, and the description never mentions it, so nothing explains whether it caps extracted cards, defaults to 20, or caps at 60. Only the type, default and bounds are discoverable from the schema itself, so the description adds no meaning here.

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 states a concrete verb pair (open + extract) and a specific resource (the Pinduoduo mobile homepage/category product cards), which clearly separates it from siblings such as pdd_search and pdd_read_item. It stops short of explicitly naming a sibling as the alternative, so it is clear but not fully differentiated.

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?

Usage is only implied: an agent can infer this is for browsing the default feed rather than running a query, and that search should go to pdd_search. There is no explicit when-to-use statement, no mention of whether login (pdd_login) is a prerequisite, and no exclusions.

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