control_spotify

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

Annotations declare a non-readonly, non-idempotent, open-world operation, and the description adds material context beyond them: it needs opt-in and playback permission, acceptance is not confirmation that audio played, and blind retries of skips are unsafe. The one gap is that it never mentions what the call returns or how to detect failure.

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?

Five short sentences, no filler, with the scope and the permission prerequisite front-loaded before the operational caveats. Every sentence carries distinct information.

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 side-effecting playback tool with no output schema, it covers the important unknowns: permissions, implicit device targeting, and the unreliability of success signals. The missing piece is what a successful response actually contains and how 'device_id' should be sourced.

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 description must compensate, and it only partially does: it explains that 'uri' selects music (a Spotify URI). 'action' and 'device_id' get no explanation at all, and device targeting is only obliquely implied by 'active Spotify Connect device'.

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 ('Control Spotify') and scopes it to 'an active Spotify Connect device', which cleanly separates it from list_spotify_devices and get_current_media in the sibling list. It does not name the individual actions, but the enum in the schema covers that.

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?

Gives real prerequisites ('Explicit opt-in and Spotify playback permission required') and a retry caution, which is more than most. However it never tells the agent how to pick the target device or that list_spotify_devices is the way to obtain a device_id, and it does not state when not to use it.

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