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

With no annotations, the description carries the full burden and does so well: it discloses cost ('免费'), data handling ('不留存'), the hard 200-item ceiling, and critically the temporal semantics that this is a point-in-time photo rather than a subscription. It also asserts implementation parity with HTTP POST /v1/resolve/batch so behavior is predictable across surfaces. Only auth/error behavior is left unstated.

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 purpose and return shape, then the caveat about monitoring, then the HTTP-parity note. It is a single dense paragraph with little waste, though the parenthetical breakdown of anomaly categories and summary-card metrics makes it slightly heavy for a one-parameter 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?

No output schema exists, so the description must describe returns, and it does: summary card fields, severity-bucketed anomaly categories, and per-device detail. Cost, retention and staleness are covered. What is missing is behavior on invalid or partially resolvable CVINs within a 200-item batch.

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 100% and the single cvins parameter already documents the 200-item max and the tolerance for a single delimited string. The description restates the 200 cap but adds no new semantics about ordering, duplicates, or partial-failure handling. Baseline 3 applies when the schema does the heavy lifting.

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 specific verb and resource ('一次解析最多 200 个 CVIN') plus exactly what comes back: summary card with registration rate/activity/in-pledge/duplicate-mortgage metrics, a severity-classified anomaly list, and per-device detail. The batch/200-cap framing implicitly separates it from cvin_resolve, but no sibling is named, so an agent still has to infer that single lookups go elsewhere.

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 clear when-to-use ('this moment's snapshot') and an explicit when-not: continuous monitoring of device loss or mortgage-right changes requires POST /v1/watch at $0.60/device/month. That is a real exclusion with a stated alternative, though the alternative is an HTTP endpoint rather than a sibling tool, and no guidance distinguishes this from cvin_resolve, cvin_risk_signals or cvin_events.

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