Next wallpaper (verified)

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

With no annotations, the description must disclose behavioral traits. It states that the tool mutates state (switches background) and reports the resulting path. However, it omits potential side effects (e.g., whether the change persists, whether it wraps around, or what happens if no next background exists). The basic behavior is clear, but some transparency is missing.

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, focused sentence that front-loads the action and result. There is no wasted wording, and the structure is clear and efficient.

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 parameters and no output schema, the description is mostly complete. It conveys the core action and the return value. However, it does not specify what happens if there is no next background (e.g., an error or no-op), which could leave an agent uncertain in edge cases. Given the simplicity, this minor gap is acceptable.

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 zero parameters, so the description does not need to explain parameter meanings. The baseline for 0 params is 4, and the description appropriately adds no unnecessary parameter detail. The action is self-contained.

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 ('Switch to the next background'), the scope ('for the current theme'), and the output ('report the resulting path'). This is a distinct, actionable purpose that differentiates it from sibling tools like theme_set or background_set_local.

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 gives no explicit guidance on when to use this tool versus alternatives. It does not mention when to avoid it, nor does it contrast with tools like background_set_local or theme_list. The usage is implied by the name and description but not articulated.

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