spotify-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not clarify what constitutes an 'available' device (active, online, authorized), mention authentication requirements, caching behavior, or whether offline/inactive devices are included in the response.

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 a single, efficient sentence with zero redundancy. It front-loads the action and target resource immediately without filler text.

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?

While the presence of an output schema reduces the need to describe return values, the description remains minimal. It lacks context about user scope (current user only), network requirements, or the relationship between 'available' devices and the Spotify Connect ecosystem.

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 contains zero parameters. Per the rubric, this establishes a baseline score of 4, as there are no parameter semantics to clarify beyond what the empty schema already communicates.

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 ('List') and resource ('Spotify Connect devices'), clearly indicating it retrieves available playback devices. However, it does not differentiate from sibling tools like 'spotify_transfer_playback' that consume device IDs or 'spotify_now_playing' that might also reference 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 description provides no guidance on when to use this tool versus alternatives. It fails to mention that this tool is typically a prerequisite for 'spotify_transfer_playback' or that it requires an active Spotify session to return meaningful results.

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