render_image

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

With no annotations, the description carries the full burden. It does disclose useful traits: the camera is auto-created if missing, output is both a preview and a saved file path, and AgX colour management is applied. It omits key behavior — that rendering is expensive/long-running, whether output_path is overwritten, and resolution/percentage side effects.

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 tight sentences with the core behavior front-loaded and the engine hint trailing. No filler, though the engine guidance is somewhat orphaned from the rest of the parameter discussion.

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 exists, but the description does state the return shape (preview image + saved file path), which helps. Still, for a 9-parameter render tool with 44% coverage and no annotations, the description is too thin to fully arm an agent — missing cost, default resolution behavior, and file-overwrite semantics.

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 coverage is only 44% across 9 parameters, so the description should compensate more. It adds meaning for `engine` (cycles for glass/liquids/interiors) and levers off the AgX `look`, but leaves exposure, resolution, percentage, transparent, and max_size semantics untouched beyond the schema text.

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?

States a concrete verb+resource ('Final render through the scene camera') with distinctive scope markers (AgX colour management, auto-created camera, returns preview + saved path). It implicitly distinguishes from viewport_screenshot via 'Final', but never names or contrasts with a sibling explicitly.

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?

Gives one conditional: 'Use cycles for glass/liquids/interiors when quality matters,' which is genuine when-to-use guidance for the engine choice. However, it says nothing about when to prefer this over look / viewport_screenshot / review_model, nor about cost, latency, or prerequisites before calling.

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