playlists_focus_previous

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

No annotations are provided, so the description carries full burden. 'Focus' implies a state change, but the description doesn't disclose whether this is a read-only operation, what happens if no previous playlist exists, whether it requires specific permissions, or what the visual/functional outcome is. It lacks behavioral context beyond the basic action.

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 zero waste. It directly states the tool's action without fluff or redundancy, making it highly efficient and easy to parse.

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 tool with no annotations, no output schema, and 0 parameters, the description is minimal but insufficient. It doesn't explain what 'focus' entails, what happens upon invocation, or how it integrates with the system (e.g., UI changes, state updates). Given the complexity implied by many sibling tools, more context is needed for an agent to use it correctly.

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 score of 4 for not adding unnecessary information.

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 'Focus the previous playlist' clearly states the action (focus) and resource (playlist), but is vague about what 'focus' means operationally. It distinguishes from siblings like 'playlists_focus_next' by specifying 'previous', but doesn't explain how this differs from 'playlists_focus' or 'playlists_focus_active_presentation' in the broader context.

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. With many sibling tools like 'playlists_focus_next', 'playlists_focus_active_presentation', and 'playlists_focus', the description doesn't indicate prerequisites (e.g., requires an existing focused playlist), exclusions, or contextual triggers.

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