transfer_playback

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

With no annotations provided, the description carries the full burden of explaining the tool's behavior. It does disclose the return format and potential exceptions, which gives some transparency about outcomes. However, it omits broader behavioral context like whether the operation is reversible, whether it requires an active playback session, or what happens to the previous device's state. Given the simplicity of the operation, this is adequate but not thorough, warranting a 3.

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 well-structured with a front-loaded one-sentence purpose followed by clear sections for Parameters, Returns, and Raises. Every section is concise and contributes necessary information without redundancy. It is appropriately sized for a simple one-parameter tool and easy to scan.

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 simplicity—one parameter, no nested objects, and an output schema—the description is complete. It covers the parameter meaning, the exact return value, and the error scenarios, leaving no ambiguity. The absence of annotations is compensated by the explanation of return behavior and exceptions, making the tool fully self-contained.

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 only defines device_id as a string with no description, but the description explicitly states 'The Spotify device ID to transfer playback to,' providing essential meaning beyond the schema. Since schema description coverage is 0%, this is a critical addition and is done clearly. It doesn't elaborate on how to obtain the ID, but the semantic meaning is fully conveyed.

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's function with a specific verb and resource: 'Transfer Spotify playback to a specific device.' This distinguishes it from sibling tools like play_pause, skip_track, or get_devices, all of which have different purposes. The one-sentence summary is unambiguous and immediately understandable.

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?

There is no guidance on when to use this tool versus alternatives, nor does it mention prerequisites such as obtaining a device ID from get_devices or ensuring playback is active. The description only states what the tool does, not when it should be invoked. This is a clear gap that leaves the agent to infer usage context from the tool name alone.

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