spotify_previous

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

The description discloses no side effects, error conditions, or requirements. It does not state what happens if no previous track exists or if playback is not active. With no annotations, the description bears full responsibility for behavioral transparency, and it falls short.

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 is a single, concise sentence with no redundant information. It is well-structured for its simplicity and delivers the core message 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?

Given the simple action and minimal schema, the description is adequate for the basic purpose but lacks any surrounding context about usage workflow or integration with other Spotify actions. It is not incomplete enough to fail, but it could benefit from brief context.

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 schema fully describes the only parameter (device_id as optional), so schema coverage is 100%. The tool description adds no extra meaning beyond the schema, but the baseline of 3 is appropriate given the high schema coverage.

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 clearly states the action 'play previous song' in Chinese, which is specific and distinct from sibling tools like 'spotify_next' (next) and 'spotify_pause'. It is concise but unambiguous about the tool's core function.

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?

No guidance is provided on when to use this tool versus alternatives. There is no mention of prerequisites such as authentication, active playback, or device availability. The description offers only the action, leaving the agent without contextual cues for tool selection.

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