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

With no annotations, the description must carry the full behavioral burden. It does disclose the return payload (matched CVIN list, match reasons, next steps) and the cost ('免费'), which is genuinely useful. It says nothing about no-match behavior, multiple/ambiguous matches, or read-only semantics beyond the implied 'lookup', leaving the safety and failure profile 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?

Two compact clauses, front-loaded with the core claim ('万能查询'), followed by the accepted inputs and the return/cost note. Every phrase carries information and nothing is padded.

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?

For a one-parameter lookup with full schema coverage and no output schema, the description covers accepted inputs, return content, and cost. It falls short only on ambiguity/no-match behavior and on routing versus cvin_resolve, which keeps it from being fully complete.

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 parameter already documents the accepted value types (serial, link, host id, asset tag, model name, CVIN). The description's enumeration largely restates that schema, so baseline 3 applies with no added syntax or format detail.

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 uses a concrete verb and resource ('万能查询' / universal lookup on CVIN) and enumerates the identifier types it accepts (CVIN, GPU serial, cloud link/host id, asset tag, invoice number, model name), so an agent can tell this is the entry-point resolver. It does not differentiate itself from the sibling cvin_resolve, which appears to occupy adjacent territory, so sibling disambiguation is incomplete.

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?

'不需要用户先学会 CVIN' plus '用户手里实际有的那个东西' gives a clear condition for use: call this whenever the agent holds any raw identifier and does not yet have a CVIN. There are no explicit exclusions or pointers to alternatives such as cvin_resolve, so the when-not guidance is absent.

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