world_to_screen

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

With no annotations provided, the description carries full burden. It discloses key behavioral traits: visibility and behind-camera flags. However, it does not mention error handling (e.g., division by zero) or performance implications, which would make it more transparent.

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 of 19 words. Every word is necessary; it states the action, the inputs, and the outputs. No filler or redundancy.

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?

Given the complexity of the tool (3D projection, multiple parameters, enums) and lack of output schema, the description is insufficient. It does not explain the return value format, coordinate system conventions, or the effect of parameters like yDirection and clipDepthRange.

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 only 17%, but the description adds minimal parameter-specific meaning. It references the combined matrix but does not explain the other five parameters (e.g., yDirection, clipDepthRange), which are underdocumented in the schema as well.

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 tool projects a world-space 3D point to 2D pixels using a combined projection*view matrix, and mentions visibility and behind-camera flags. This is a specific verb+resource combination that distinguishes it from sibling tools like world_to_view or view_to_clip.

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 does not explicitly state when to use this tool versus alternatives. It implies usage for converting a world point to screen coordinates, but gives no guidance on prerequisites or when not to use it, especially given the presence of sibling tools for intermediate steps.

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