list_ports

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

With no annotations, the description carries the full burden for behavioral disclosure. It discloses the heuristic nature of chip identification ('best-guess'), which is a valuable reliability caveat. It does not detail side effects or permissions, but a listing operation is implicitly non-destructive.

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, front-loaded sentence that states the primary action and key caveat. Every word adds value, with no repetition or irrelevant detail.

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 simple listing tool with an output schema and no parameters, the description covers the essential purpose and the notable 'best-guess' caveat. It could be slightly more explicit about typical use cases, but it is complete enough for an agent to decide when to invoke this tool.

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, so the baseline is 4. The description does not need to add parameter details, and the schema already reflects this with an empty properties object.

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 action ('List'), the resource ('serial ports'), and adds specific scope ('including the simulator') and a notable feature ('best-guess chip identification'). This distinguishes it from sibling tools like board_info and flash_firmware, making the purpose unambiguous.

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 phrase 'including the simulator' provides clear context that this tool is intended for enumerating both physical and simulated port environments. While it does not explicitly mention alternatives, the context is sufficient for selecting this tool over siblings in a development workflow.

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