pio_list_devices

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

With no annotations, the description carries the behavioral burden, and it does so well: it reveals that the tool lists serial ports and heuristically flags device types (CP210x, CH340, FTDI, ESP, Arduino, ST-Link). This is a read-only listing operation and the description makes that evident without needing explicit side-effect warnings.

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 two compact sentences with no filler. The primary action is front-loaded, and the second sentence adds practical value by explaining what to do with the output.

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, read-only listing tool with an output schema available, the description provides all necessary invocation context: what is listed, how results are classified, and how to use the result with related tools. Nothing essential 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 is empty with zero parameters, so there is nothing for the description to clarify. The baseline for zero-parameter tools is 4, and the description appropriately focuses on behavior rather than inventing parameter details.

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 action and resource: list serial ports and flag likely USB dev boards, which is much more informative than the tool name alone. It also differentiates from siblings like pio_list_boards and pio_list_targets by focusing on connected serial devices rather than supported boards or build targets.

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 gives clear downstream guidance: use the resulting port with pio_upload, pio_monitor_start, or pio_monitor_capture. It does not explicitly name alternatives to avoid or state when not to use this tool, but the intended workflow is clear.

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