playlists_trigger_focused_previous

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

With no annotations provided, the description carries full burden but only states the action without behavioral details. It doesn't disclose whether this is a read-only or mutating operation, what happens if no playlist is focused, if it requires specific permissions, or what the expected outcome is (e.g., playback change). This leaves significant gaps for a tool that likely triggers media playback.

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, efficient sentence that directly states the tool's purpose with zero wasted words. It's appropriately sized for a simple, parameterless action and is front-loaded with the core functionality.

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 parameterless tool with no output schema, the description is minimally complete but lacks important context. It doesn't explain what 'triggering' entails (e.g., starting playback, advancing a cursor), what a 'focused playlist' is, or what happens on success/failure. Given the likely media control context, more behavioral detail would be helpful despite the simple structure.

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 has 0 parameters with 100% schema description coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, earning a baseline high score since it doesn't need to compensate for any schema gaps.

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 ('Trigger') and target ('the previous item in the focused playlist'), providing specific verb+resource. However, it doesn't explicitly distinguish itself from sibling tools like 'playlists_trigger_focused_next' or 'playlists_trigger_previous', which would require mentioning the 'focused' context to differentiate.

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 doesn't mention prerequisites (e.g., needing a focused playlist), exclusions, or compare to similar tools like 'audio_trigger_focused_previous' or 'playlists_trigger_previous', leaving the agent to infer usage from context alone.

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