音量取得

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

The readOnlyHint annotation already covers the safety profile, and the description adds that it reports both volume and mute state. However, it does not disclose return format, default-device behavior, or failure cases, though for a simple read operation this is not a major gap.

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 a single concise sentence with no filler. It front-loads the action and directly states what is returned.

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 simple read-only tool with one optional documented parameter, the description is sufficient for an agent to invoke it correctly. The lack of an output schema leaves the exact return structure unspecified, but the described content is clear enough for this use case.

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 single optional device parameter is fully described in the input schema (100% coverage), including its default resolution behavior. The description adds no additional parameter context, so the baseline score of 3 applies.

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 clearly states the operation ('返す') and the resource ('現在の音量とミュート状態'), making it unambiguous that this is a read-only query for volume and mute status. It is also naturally distinguishable from sibling mutation tools like set_volume, mute, and volume_up/down.

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 the tool is for retrieving current state rather than changing it, but it does not explicitly say when to use it over alternatives or mention any exclusions. The sibling names provide context, but the description itself offers no direct usage guidance.

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