preview_gcode

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

No annotations exist, so the description must carry the full burden. It discloses the output format and the valid size range, but says nothing about read-only safety, error behavior for bad paths, render cost, or whether the image is returned inline.

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?

Dense and front-loaded: the render target comes first, then parameter meaning, then the color legend. It's a bit run-on and the missing line breaks make the layer/color enumeration harder to scan, but no sentence is filler.

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 3-param read tool with no output schema, the description covers output format, both modes, the color legend, and the size constraint. An agent could invoke it correctly from this plus the schema.

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 0%, so the description must compensate and largely does: size is defined as image edge in pixels with a 200-2000 bound, and layer is defined as 1-based with None meaning all layers shaded by height. Only 'path' is left implicit (a .gcode file), which is a minor gap rather than a real ambiguity.

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?

Opens with a specific verb+resource+format: 'Top-down PNG render of a .gcode'. An agent can distinguish this from gcode_summary or model_info, though the description never explicitly contrasts it with those 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?

It clearly explains the two operating modes (layer=None for footprint/placement check vs layer=N for per-feature inspection), which tells the agent which mode to pick. It stops short of naming alternatives or when not to call it.

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