blender_world_shader

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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the description doesn't need to restate those. The description adds useful context about the Nishita daylight environment suggestion, but it doesn't disclose what happens to an existing world shader, whether the operation replaces or modifies the current world, or whether it requires an active scene. With annotations covering the safety profile, a 3 is appropriate.

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 sentences with zero waste. The first sentence lists the four shader types, and the second provides a practical recommendation. The most important information is front-loaded.

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?

The tool has 14 parameters, no required parameters, and no output schema. The description covers the high-level purpose and a usage tip, but it doesn't explain the relationship between the many optional parameters (e.g., when angle vs sun_rotation applies, or how strength interacts with type). For a tool with this many parameters, the description is adequate but leaves the agent to infer parameter combinations from the schema alone.

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 79%, so the schema already documents most parameters. The description adds a helpful hint that 'Nishita with sun elevation gives a believable daylight environment', which maps to sky_type and sun_elevation, but it doesn't explain the interplay between type, sky_type, angle, and rotation beyond what the schema provides. Baseline 3 is correct when the schema does most of the work.

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 states a specific verb ('Build') and resource ('world shader'), and enumerates the four supported shader types (flat colour, vertical gradient, physical sky, HDRI image). It also names the Nishita sky model with sun elevation as a recommended option, which distinguishes this tool from siblings like blender_make_material or blender_build_shader.

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 clear context for when to use this tool: when building a world shader, and it even suggests Nishita with sun elevation as a lightweight alternative to HDRI downloads. It does not explicitly name sibling alternatives or state when not to use it, but the context is strong enough for an agent to select it appropriately among the many blender_* tools.

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