media

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the tool controls media without the screen and that status reports what is playing, but it does not explain permissions, side effects, error behavior, or whether volume affects the media stream versus the device.

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 efficient sentence that front-loads the core purpose and enumerates actions without unnecessary repetition. Every clause contributes to understanding the tool's scope.

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?

Given the absence of an output schema and annotations, the description is only minimally complete. It does not specify what status returns beyond 'what's playing,' nor does it cover the omitted toggle action or conditional volume requirement.

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 description lists most action values and mentions setting media volume, which adds meaning beyond the bare enum. However, it omits the 'toggle' action entirely and does not clarify that the volume parameter is only required when action is 'volume'.

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 and resource: controlling phone media playback for music, podcasts, and videos. It enumerates the main actions and clarifies that the tool works without the screen, which helps distinguish it from screen interaction siblings, but it does not explicitly name alternatives.

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 by listing capabilities such as play, pause, and status, but it gives no explicit when-to-use or when-not-to-use guidance. It does not point to alternatives like read_screen or tap, so an agent must infer the selection criteria.

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