List Devices

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

No annotations are provided, so the description carries the full behavioral burden. It says the tool lists 'every' device, implying enumerations are complete, but says nothing about authentication requirements, behavior when no sessions are active, or whether the list reflects idle vs. active devices — notable given the spotify_login/logout siblings.

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?

One short sentence with the verb and scope front-loaded, and the parenthetical examples earn their place by clarifying device coverage. Nothing is wasted.

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?

An output schema exists and the tool is parameterless, which covers a lot. The remaining gap is operational context: whether a logged-in session is required and how the list relates to playback targets, both of which an agent needs to call this correctly at the right moment.

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 tool takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies for a parameterless tool.

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?

States a specific verb+resource (list Spotify Connect devices) and enriches it with concrete examples of device types. It does not, however, distinguish itself from the sibling cleanup_devices, which also operates on the device list.

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?

There is no guidance on when to call this versus cleanup_devices, nor any mention of prerequisites (e.g., needing an authenticated session before the device list is populated). The agent must infer the use case from the tool name alone.

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