list_serial_ports

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

With no annotations provided, the description carries the full burden. It adds useful behavioral context beyond the name: USB-RS485 adapters show VID:PID and manufacturer hints, and it is cheap to try connecting to another port. It doesn't describe the exact return format or edge cases like no ports found, but for a harmless listing operation the provided context is solid.

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 front-loaded with the core purpose and call order, then adds only useful interpretive guidance. Each sentence earns its place, and there is no fluff.

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, no-output-schema listing tool, the description is complete: it tells the agent when to call it, what to expect in the output, how to handle ambiguity, and what to do next. Nothing essential is missing for correct invocation.

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 correctly does not need to explain parameters and instead focuses on what the operation returns and how to interpret it.

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 specific verb and resource: 'List the serial ports on this computer'. It also states the purpose, 'so one can be chosen for connect', and clearly positions this tool as the first step in a session, distinguishing it from sibling tools like connect and list_motors.

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?

It gives explicit, strong usage guidance: 'Call this FIRST in any session.' It also explains how to handle multiple adapters and ambiguity. It does not explicitly name alternative tools or when not to use them, but the context is clear enough.

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