music_previous_track

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 implies a playback-state mutation but does not disclose whether playback must be active, what happens if there is no previous track, whether playback continues or restarts, or whether the Music app must be running.

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 front-loaded sentence with no wasted words. It is appropriately sized for a zero-parameter playback-control action.

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 low complexity, empty parameter schema, and no output schema, the description is mostly complete enough to call the tool. It could be stronger by stating prerequisites or the fallback behavior when no previous track exists, but those gaps are relatively minor for this simple action.

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 parameter semantics are inherently simple and the baseline is 4. There is no parameter documentation needed beyond the empty schema.

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 states a specific verb and resource: going back to the previous track in the Music app. It is clearly distinct from music_next_track by the word "previous," but it does not explicitly name or contrast with any sibling tool.

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?

Usage is only implied by the tool name and phrase "goes back to the previous track." There is no explicit guidance on when to use this versus music_next_track, music_play, or music_pause, and no stated prerequisites such as Music app being open or playback being active.

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