imgui_set_background

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

No annotations are provided, so the description carries the transparency burden. It clearly states this sets the background clear color but doesn't disclose side effects (e.g., whether the change persists across frames, whether it requires a subsequent draw call, or whether it affects all subsequent renders). For a state-mutation tool, modest additional behavioral context would be valuable, though 'clear color' does imply render-relevant state.

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?

A single clean sentence that states the action and the target resource with zero waste. No filler, no redundancy. Every word earns its place.

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 simple one-parameter color-setting tool with 100% schema coverage and no output schema, the description is largely adequate. However, it doesn't address whether the color change takes immediate effect, whether it persists, or how it interacts with the imgui_draw flow. For such a simple tool this is a reasonable but not exhaustive description.

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?

Schema description coverage is 100% (the color parameter is fully documented with [r,g,b] range 0.0-1.0), which sets the baseline at 3. The description adds value by clarifying that the color is applied to the background clear color of the viewport, giving the parameter real-world context beyond the schema's raw RGB specification. However, it doesn't add detail beyond what the schema's parameter description conveys.

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 'Set the background clear color of the viewport' uses a specific verb+resource (set + background clear color of viewport), clearly stating what the tool does. It distinguishes itself from most siblings which handle widgets, windows, screenshots, or input, though it could be slightly confused with imgui_set_style/push_style_color which affect colors too.

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 implies when to use it (when you want to change the viewport's background clear color) but provides no explicit guidance about when not to use it or alternatives. Given siblings like imgui_set_style, imgui_set_theme_color, and imgui_push_style_color also touch colors, some exclusionary guidance would help disambiguate background clear color from style/theme colors.

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