preview_model

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

No annotations are supplied, so the description carries the full burden. It does add one genuine behavioral trait beyond the schema — 'Fast, non-blocking' — which tells the agent the call returns asynchronously rather than waiting on the render. It omits other important traits: where the PNG output is written, whether a pipeline/model must be loaded first, and how errors surface.

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?

Three short sentences with the core action front-loaded and the behavioral note ('Fast, non-blocking') placed immediately after, so the most important information is read first. Nothing is padded, though the closing capabilities sentence is partly redundant with the schema.

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?

With no output schema and no annotations, the description should explain the result of a render: where the PNGs land, what a sequence returns, and any prerequisite pipeline state. It covers the input side adequately (via the schema) but leaves the output and precondition side of a rendering tool under-specified.

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 100%, so all three parameters (max_size, glb_paths, input_path) are already documented, including the 'alternative to' relationship. The description's mention of 'single files, sequences, and IFL files' restates the input_path schema description rather than adding new format or syntax detail, so the baseline of 3 applies.

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 specific verb and resource ('Render GLB models to preview PNG images') plus the underlying engine ('3d-to-image'), so the agent knows exactly what it produces. It does not, however, differentiate itself from the sibling preview_model_sequence, and its claim to support 'sequences and IFL files' actively overlaps with that sibling.

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?

There is no statement of when to use this tool versus preview_model_sequence, preview_images, or any of the load/unload pipeline siblings. The sentence about supported input types is descriptive capability, not usage guidance, so the agent must infer selection from names alone.

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