set_world_background

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

With no annotations, the description takes on the behavioral burden and adds a useful non-obvious fact: strength of 0 makes shadows pitch black, i.e., the world is a light source. It does not disclose every edge case such as what a null color means, but it goes beyond a bare setter.

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?

Two short sentences with the core action front-loaded and no filler. The behavioral explainer is earned because it clarifies what strength actually does.

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 two-optional-parameter tool with a complete input schema, this description is nearly sufficient. The only notable gap is not describing what passing color=null means and not mentioning the output/return behavior, but neither is critical for basic use.

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 schema already covers both parameters thoroughly (100% coverage), so the baseline is 3. The description adds real semantic value for strength by explaining its visual effect on shadows, though it does not add anything about the color parameter or its null default.

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 uses a specific verb and resource: it sets the world background's colour and strength, which clearly distinguishes it from object/light/render tools. It does not explicitly contrast with siblings like set_render_settings or create_light, so it misses the strongest possible differentiation.

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 note that 'the world lights the scene' implies this tool controls ambient/global lighting, giving the agent some situational cue about when it matters. However, there is no explicit when-to-use, when-not-to-use, or mention of alternatives such as set_light_properties or set_render_settings.

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