list_ports

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only restates the basic purpose and does not disclose return format, scanning behavior, permission requirements, or error conditions. For a listing operation, additional context like what information is returned would be expected.

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 sentence — "List available serial ports" — with no wasted words. It is front-loaded with the verb and directly conveys the action. Every word contributes meaning.

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 zero-parameter listing tool with no output schema, the description is minimally adequate: it conveys the essential purpose. However, since there is no output schema, the description could have disclosed return value details (e.g., port names, paths, metadata), which would improve completeness.

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 (empty schema, 100% schema coverage), so the baseline is 4. The description does not need to add parameter meaning since there are none; 'available' offers a slight scope hint but no parameter documentation is required.

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: "List available serial ports" — a specific verb ('List') with a specific resource ('available serial ports'). It distinguishes from siblings (open_port, close_port, send_command, etc.) since no other sibling tool lists ports, though it does so implicitly rather than explicitly.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention prerequisites, exclusions, or recommend alternatives from the sibling set. There is no stated context such as 'use before open_port' or 'use to discover available devices'.

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