ndc_to_screen

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

No annotations provided, so description carries full burden. It states the scaling operation and notes yDirection for origin, but does not describe how the z component of ndcPoint is handled, nor the return format (e.g., screen coordinates as floats or ints). Adequate but minimal.

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?

Single sentence, concise and front-loaded with purpose. However, it could be slightly more structured by separating the primary action from optional parameter behavior (yDirection).

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?

No output schema, no annotations, and a nested parameter object. The description covers the basic transformation but omits what the tool returns (e.g., an object with screen x,y) and how z is treated. For a simple math tool, it is marginally complete.

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 50% (ndcPoint and yDirection have descriptions, width and height have constraints). The tool description adds no additional explanation for parameters, missing an opportunity to clarify, e.g., the range of width/height or the mapping from NDC to screen pixels.

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?

Description uses a specific verb ('Scales') and resource ('normalized device coordinates to a 2D screen resolution'), clearly distinguishing it from siblings like 'world_to_screen' which operate at a different coordinate stage.

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?

No guidance on when to use this tool vs alternatives such as 'world_to_screen' or 'clip_to_ndc'. The description does not mention prerequisites or preferred contexts.

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