render_probe

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

Annotations already declare the tool read-only and non-destructive. The description adds useful behavioral detail by explaining that it returns a 'warnings' list naming the broken stage or a verdict that geometry reaches the camera. It also points to help(tool=...) for the full stage list, which is helpful context beyond the annotations.

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 compact and front-loaded with the tool's purpose, followed by output behavior and a clear usage directive. The illustrative scenario sentence adds color but does not waste much space, and the help pointer is efficient.

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 description adequately covers the high-level purpose, return value, and when to use the tool, and the annotations cover safety. However, the five optional parameters are left mostly undefined and there is no output schema, so an agent may struggle to construct a correct call beyond a simple path-based probe.

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 20%, with just 'path' documented. The description does not explain 'nth', 'name', 'class', or 'under', and it does little to clarify how these optional parameters identify the node being probed. Since the schema is sparse, the description should compensate but does not.

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 identifies a diagnostic tool for determining why a 3D node is or is not visible, and distinguishes it from pixel-based tools by saying 'as data instead of pixels'. It also names the exact scenario it addresses, making it easy to differentiate from screenshot or UI inspection siblings.

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 strong situational guidance: 'USE THIS BEFORE tuning lighting, fog, exposure or palette on anything you cannot clearly see.' It does not explicitly name alternatives or exclusions, but the 'instead of pixels' phrasing and the strong directive make the intended usage clear.

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