list_serial_ports

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

With no annotations provided, the description carries the burden of behavioral disclosure. It discloses what the tool returns—system name, human description, and USB hardware id—and implies a safe, read-only discovery operation, though it does not explicitly state that it has no side effects.

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 short, front-loaded with the core function, and every sentence adds value: what is listed, when to call it, and what the output is useful for.

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 parameterless discovery tool with an output schema, the description fully covers why an agent would invoke it, when to invoke it, and what the result enables. No essential guidance is missing.

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 input schema has zero parameters, so there is nothing to document. The description adds relevant context by explaining how the returned values are meant to be used, which is more than necessary for a parameterless call.

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 states a specific verb and object: 'List every serial port the computer can currently see.' It clearly distinguishes this tool from siblings like connect, send_text, and read_available, which perform different operations on a chosen port.

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 explicitly tells the agent when to call this tool: call it FIRST when connecting to a device without an exact port name, or when a connection fails. It also frames the output as the port name to pass to `connect`, making the relationship to the primary sibling tool clear.

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