atv_now_playing

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

With no annotations provided, the description must disclose behavioral traits itself. It lists output fields, implying it is a read operation, but it does not explicitly state whether it modifies state, requires authentication, or how it behaves on error. The description adds minimal behavioral context beyond what the name suggests.

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 that fronts the purpose. It is appropriately short but lacks structure or any breakdown of parameters or usage. It is minimal but not misleading, though it omits essential details.

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 tool's low complexity (one optional parameter, no output schema provided), the description should cover purpose, usage, parameters, and behavior. It covers purpose partially and output fields, but omits the device parameter, usage context, and any behavioral guarantees. For a tool with many siblings, this is insufficient for an agent to decide when and how to invoke it correctly.

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 schema has zero description coverage for the 'device' parameter, and the description does not mention it at all. This leaves the parameter's meaning entirely unexplained. The description fails to compensate for the schema's lack of information.

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 tool retrieves current playback information and lists the specific fields (title, artist/app, position, state). It distinguishes itself from sibling tools like atv_play or atv_power by focusing on querying rather than controlling.

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 provides no guidance on when to use this tool versus alternatives. It does not mention exclusions, prerequisites, or context that would help an agent choose between atv_now_playing and sibling tools like atv_play or atv_devices.

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