spotify_is_device_active

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

No annotations are provided, so the description carries the full burden. It states the return type ('true' or 'false' as text) and implies idempotency and no side effects. However, it doesn't disclose potential prerequisites (e.g., active Spotify session) or error conditions. Given the minimal behavioral scope, the description is adequate but not comprehensive.

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 sentence followed by a brief note on return format. Every word adds value: 'ONLY' clarifies it's a simple check, and the return explanation is helpful. No redundancy or irrelevant information.

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 parameterless tool with no output schema, the description covers the essential: what it does and what it returns. It could mention that it requires an active Spotify device or connection, but that might be assumed. The description is nearly complete for its scope.

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 input schema has no parameters, so schema_description_coverage is effectively 100%. Per the rubric, 0 parameters yields a baseline of 4. The description adds no parameter info, but none is needed.

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 purpose: to get whether a device is currently active. It uses the verb 'Get' and specifies the resource 'device active status'. The name 'spotify_is_device_active' aligns well with the description, and it is distinct from siblings like 'spotify_get_available_devices' which lists all devices rather than checking active status.

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 use when needing a simple boolean check for device activity. It doesn't explicitly state when not to use it or provide alternatives, but the simplicity of the tool (no parameters) makes the context clear. A slight improvement would be to mention that this tool is for quick status checks rather than detailed device info.

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