set_volume

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

With no annotations, the description carries the full burden. It discloses a key constraint (Premium account) and the effect (set volume), but does not mention behavior like applying to the active device, side effects on current playback, or failure modes when no device is active. The schema partially covers device behavior, but the description adds little beyond the action itself.

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, front-loaded sentence that conveys the core action and a key requirement in under ten words. Every word earns its place, with no redundancy or unnecessary detail.

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 simple two-parameter setter with a fully described schema and no output schema, the description is sufficient to convey the primary purpose and a critical prerequisite. It lacks some detail about device selection and failure behavior, but these are partially covered by the schema, and the tool's simplicity does not demand extensive elaboration.

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 coverage is 100%, with clear descriptions for both deviceId and volumePercent. The description adds only the parenthetical range (0-100%), which is already present in the schema, so it provides no additional semantic value beyond the structured definitions.

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 ('Set') and resource ('playback volume') with an explicit range (0-100%). It is immediately distinct from the sibling playback controls like play, pause, and next_track, leaving no ambiguity about what the tool does.

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?

No direct 'when to use' guidance or alternatives are stated. The only guidance is the prerequisite 'Requires a Spotify Premium account,' which implies usage but does not explain how this tool fits among playback controls or when one might prefer it.

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