spotify-mcp

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

With no annotations provided, the description carries the full burden. It successfully discloses the valid input range (0-100) and the Premium requirement, but fails to explain default device selection behavior when device_id is omitted, error conditions, or side effects.

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 consists of two efficient sentences with zero waste. It front-loads the core action and immediately follows with critical constraints, making it an exemplar of concise technical writing.

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 (2 parameters, straightforward mutation) and the presence of an output schema, the description is nearly sufficient. It is only missing explanation of the device_id parameter's semantics to be fully complete.

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%, requiring the description to compensate. It adds essential semantic meaning for volume_percent via the '(0-100)' range constraint, but completely omits any explanation of the optional device_id parameter and its default null behavior.

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') with a clear resource ('playback volume') and includes a critical range constraint ('0-100'). It clearly distinguishes this tool from the many playlist, search, and library management siblings in the Spotify toolset.

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 provides one key usage constraint ('Requires Premium') indicating a prerequisite, but lacks explicit guidance on when to use this versus other playback control tools or what conditions must be met (e.g., active playback session).

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