获取贵金属ETF持仓变化

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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It only states the purpose and does not elaborate on data source, update frequency, latency, or return format. For a read-only data tool this is a minor gap, but it still fails to provide any behavioral context beyond what is directly apparent from the purpose.

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?

The description is a single, efficiently worded sentence that immediately communicates the verb and resource. It is front-loaded with the core action and adds the use case without unnecessary fluff.

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?

With only two simple parameters, no output schema, and no annotations, the description provides the essential purpose and use case. However, it does not specify what the returned data looks like (e.g., time series of changes, units, or date range), which could leave the agent uncertain about the response structure. Given the simplicity, a score of 3 reflects that it is adequate but lacks some detail.

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 input schema has 100% coverage with descriptions for both parameters ('limit' and 'metal'), so the baseline is 3. The description adds no parameter-specific meaning beyond what the schema already provides, so it neither improves nor worsens the baseline.

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 clearly states the tool fetches global gold or silver ETF holdings change data, using the specific verb '获取' (fetch) and a precise resource. This distinguishes it from sibling tools like pm_spot_prices and pm_comex_inventory which focus on prices and inventories.

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 explicitly states the intended use case ('用于判断机构资金流向' – used to judge institutional fund flows), providing clear context for when to use this tool. However, it does not mention alternatives or when not to use it, so it slightly falls short of a full 5.

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