list_ports

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It implies a read-only operation by stating it lists available ports, but it does not disclose the output format, whether it modifies anything, or any system prerequisites. For a simple listing tool, this is adequate but not rich. There is no contradiction with annotations since none exist.

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 two sentences long, front-loaded with the primary action ('列出所有可用的串口'), followed by a concise usage note. Every sentence earns its place, with no superfluous content. It is compact and well-structured.

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?

Given the tool's simplicity (no parameters, no output schema, no annotations), the description is adequately complete. It states what the tool does and when to use it, which is sufficient for an agent to select and invoke the tool. It could mention the return format or that it is read-only explicitly, but those are minor omissions for a trivial list operation.

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 tool has zero parameters in the input schema, and the schema description coverage is 100%. The description adds no parameter-specific information because there are no parameters to document. Per the rubric, 0 parameters corresponds to a baseline score of 4, and the description does not need to compensate for any parameter documentation gaps.

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's function: '列出计算机上所有可用的串口（COM口）' (List all available serial ports on the computer). It uses a specific verb ('列出' / list) and resource ('串口' / serial ports), and further clarifies its purpose for finding the port of a console-connected switch. This distinguishes it from the sibling tools like connect, send_command, etc., which handle other aspects of serial communication.

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 provides clear usage context: it is used to find the port number where a switch is connected via Console cable ('用于查找通过Console线连接的交换机所在的端口号'). Although it does not explicitly mention when not to use this tool or name alternative tools, the context is sufficient for an agent to know it is a preliminary discovery step before connect or send_config. The absence of exclusions is a minor gap.

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