登録済みデバイス一覧

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds that it reads from devices.json and includes the default device, which is useful context. It doesn't disclose return format or whether the list is ordered, but for a simple read-only list tool, the annotation plus description is adequate.

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?

One sentence, front-loaded with the resource and action. No wasted words. It conveys the essential information efficiently.

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 list tool, the description is nearly complete. It states the data source and the inclusion of the default device. The only minor gap is not describing the return format (e.g., array of device objects), but with no output schema and simple semantics, this is a small omission.

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 schema is trivially complete. The description adds meaning by specifying the data source (devices.json) and that the default device is included. With no parameters, the baseline is 4, and the description provides useful context about what the returned list contains.

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 ('返す' = returns) and a clear resource: devices stored in devices.json plus the default device. It distinguishes itself from sibling tools like discover_devices, pair_device, and remove_device, which are about discovery, pairing, and removal rather than listing. However, it doesn't explicitly name a sibling alternative, so it doesn't fully differentiate from list_apps or other list tools, though the resource is clear.

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 implies usage: call this when you need the list of registered devices and the default device. It doesn't explicitly state when not to use it or mention alternatives like discover_devices for finding new devices. The context is clear enough for an agent to infer, but there is no explicit routing guidance.

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