render_viewport

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

With no annotations present, the description carries the full burden. It discloses that settle_seconds waits 'without blocking Houdini' and is 'Capped at 120' – genuinely useful behavioral details that go beyond the basic action. However, it does not mention behavior for null camera/resolution or whether anything is returned, leaving some minor gaps.

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 one-line summary followed by a compact Args list. Every sentence serves a purpose: the summary defines the action, the Args block defines inputs, and the settle_seconds note explains a non-obvious parameter. No filler or repetition.

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?

For a tool with 4 parameters, no output schema, and no annotations, the description covers the action, all parameter meanings, and a key behavioral caveat. It lacks explicit return-value documentation and default behaviors for null resolution/camera, but these are minor given the tool's simplicity. An agent could invoke it correctly based on this description.

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 0%, so the Args section is the only parameter documentation. It explains output_path as 'Image file path', resolution format '[width, height] in pixels', camera as 'Camera node path', and gives a detailed purpose-driven explanation for settle_seconds. This far exceeds the bare schema, though a note on camera's null default would make it fully complete.

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 'Capture the current 3D viewport to an image file' – a specific verb, resource, and output. This clearly distinguishes it from siblings like render_quad_view (multi-view capture) and capture_screenshot (UI-level capture). No ambiguity remains.

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 only usage guidance is 'Use this instead of a shell sleep between calls' for the settle_seconds parameter, which is a sub-parameter recommendation rather than a tool-selection rule. There is no comparison to sibling capture tools (render_quad_view, capture_screenshot) or guidance on when to prefer this tool over alternatives, so an agent must infer usage from the one-line summary alone.

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