set_playback_volume

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

No annotations are provided, so the description carries the full disclosure burden. It does reveal the operational scope (only the active device) and the valid range of 0-100, but it does not describe what happens when no device is active, how errors are surfaced, or any side effects beyond changing the volume.

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?

Two short, front-loaded sentences contain no filler or redundant restatement. The action, target scope, and parameter range are all delivered efficiently.

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 single-parameter write operation with an output schema present, the description covers the essential invocation details: what it does, where it applies, and the valid parameter range. The only notable omission is explicit guidance for the no-active-device case, but the 'active device' wording partially covers that precondition.

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 schema only provides the type ('integer') and required flag. The description compensates by explicitly adding the critical 0-100 constraint, which is the main semantic information needed to invoke this single-parameter tool correctly.

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 a specific resource ('playback volume on the user's active Spotify device'), making the tool's purpose immediately clear. This distinguishes it from sibling playback controls like pause, resume, skip, and seek, and from device management tools like activate_device and list_devices.

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 phrase 'active Spotify device' implies a precondition that a device must already be active, but the description never explicitly says when to use this tool versus activating a device or listing devices first. No alternatives or exclusion conditions are mentioned, leaving the agent to infer proper sequencing.

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