Devices

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

No annotations are provided, so the description carries the full burden. It does hint at behavior by noting 'which serials adb sees right now' (a live, dynamic snapshot) and the devices.yaml config source, which implies a non-mutating read. However, it never explicitly states read-only semantics or what happens if adb is unavailable.

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?

A single tight sentence with no waste and the key content front-loaded ('Registered devices'). It is arguably under-specified rather than over-long, but every phrase contributes information.

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 not needed, and the no-param schema is trivial. The remaining gap is contextual: the description does not clarify what 'the default' means or how an agent should act on the returned config, leaving the practical purpose slightly under-defined for an agent choosing among many siblings.

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 takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. Schema coverage is 100% and the input object is empty.

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 is a noun phrase fragment rather than a verb+resource statement, but it does enumerate the returned content: registered devices from devices.yaml, the default device, and currently adb-visible serials. An agent can infer this is a device-inventory/status read, though 'the default' is left dangling and unexplained against siblings that are all action tools.

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?

There is no when-to-use guidance at all — no statement of when an agent should consult device inventory versus calling shell or launch directly. The relationship to sibling tools like launch or check is entirely unstated.

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