再生制御

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

With no annotations, the description carries the behavioral disclosure burden. It does disclose a key trait: commands are best-effort and may be ignored by unsupported apps. However, it does not describe result reporting, failure handling, or side effects; the coverage is adequate but not rich.

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?

Two short sentences with no redundancy: the first fronts the command set, the second adds a practically important caveat. Every sentence contributes signal.

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 two-parameter command tool, the description plus fully covered schema is nearly sufficient. It includes the main caveat (app support), and the only notable gap is response/error behavior, which is minor for this tool.

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 100%, so the baseline is 3. The description restates the enum actions in prose but adds little beyond the schema; the device parameter's default behavior is already fully explained in the 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?

The description states a specific action ('sends play/pause/stop/rewind/fast-forward') and a clear resource (media control). This distinguishes it from siblings like volume, input, and app controls, even without naming them.

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 intended use is clear: use this tool when playback transport commands need to be sent. It also warns that some apps may not support the commands, which gives practical context, though it does not explicitly name alternatives or exclusion cases.

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