activate_device

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

Since no annotations are provided, the description is the only behavioral disclosure. It states the two main effects—switching playback target and optionally starting playback—but does not mention prerequisites or failure behavior. This is adequate but minimal.

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?

One sentence, front-loaded with the action, and no filler. The parenthetical source and the optional behavior are both useful and earned.

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 low-complexity two-parameter tool with an output schema, the description covers the required workflow and both parameter intents. Missing edge cases like inactive sessions or unavailable devices are minor for this simple command.

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 0%, so the description must supply meaning for the parameters. It does: 'specific device (from list_devices)' explains device_id, and 'optionally start playing' explains start_playing. The schema still carries the default value and requirement details.

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 uses a specific verb ('Switch') and a clear resource ('playback to a specific device'), and explicitly references list_devices, which distinguishes it from the listing tool and other playback controls among the siblings.

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 parenthetical '(from list_devices)' tells the agent where to get the device_id, establishing a clear call sequence. It does not provide explicit exclusions, but the usage context is unambiguous enough for tool selection.

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