list_serial_ports

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

With no annotations, the description must carry the behavioral load. It does disclose the substantive behavior — passive scanning plus classification of attached devices and chip hints — but never states that the operation is read-only/non-mutating, whether it requires serial-port permissions or group membership, or whether the scan is slow. Useful context, but incomplete for a no-annotation tool.

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?

Front-loaded with the core action in the first sentence, followed by output detail and then a compact Args block. Every line carries information; the only minor redundancy is restating parameter names already present in the schema, which is justified because the schema lacks descriptions.

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?

An output schema exists, so return-value explanation is unnecessary, and both parameters are documented in the description. What remains missing is environmental framing — cross-platform behavior and permission requirements — which matters for a hardware-scanning tool but is a moderate rather than fatal gap.

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?

Schema description coverage is 0%, so the description has to compensate, and it does: both booleans are explained in the Args block, including the non-obvious meaning of hide_phantom_ttys (unpopulated Linux /dev/ttyS* ports with 'n/a' hwid) and the default of True. Actual path formatting or symlink semantics could go further, but this is well above the bare schema.

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?

States a specific verb and resource — 'Scan and list all USB/Serial ports connected to the computer' — and goes on to enumerate what the listing surfaces (VID/PID, manufacturer, serial number, board/UART chip hints). This is clearly distinguishable from siblings such as find_port_occupiers or scan_hardware_bridges, which address different concerns.

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?

Usage is only implied: the mention of board/chip hints ('ESP32, Arduino, Pico, FTDI') suggests this is a discovery step before flashing or connecting, but the description never says when to call it or when to prefer an alternative. No exclusions or prerequisites are given.

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