place_image

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

With no annotations provided, the description carries the full burden and does so well: it discloses format-dependent results, that nodeId replaces/creates fills (and is invalid for SVG), where the new layer is placed by default, how sizing defaults work, and a real platform constraint ('Images larger than 4096 px on a side are scaled down by Figma'). It also warns that fileKey is ignored in favor of the open desktop file.

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?

A single dense paragraph with zero filler; the core action leads, followed by format outcomes, the alternative tool, and placement/sizing defaults. Every clause carries information an agent needs to call it correctly.

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 an 11-parameter mutation tool with no annotations and no output schema, the description covers outcomes, placement, sizing, limits, and the sibling alternative. It stops short of describing what is returned (e.g., the created layer's id) and leaves x/y and scaleMode/keepFills entirely to the schema, which is a minor but real gap.

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 64%, and the description compensates on the weakest spots: width/height have no schema description but are explained ('one keeps the aspect ratio; default: the image's own size'), as are nodeId, parentId defaults, and fileKey. However x/y placement and scaleMode/keepFills behavior get no narrative treatment in the description beyond their 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 specific verb and resource ('Put an image file from this computer into the file open in Figma Desktop') and immediately names the outcome variants (raster -> image-fill rectangle, SVG -> editable vectors). It explicitly contrasts itself with the sibling use_figma, so an agent can distinguish the two without opening either schema.

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 an explicit when-to-use rule ('Use it for the project's own assets (logos, icons, photos) while designing') and names the alternative with its exact call signature ('use_figma with figma.createImageAsync(url) takes images from the web'). It also states a within-tool branch condition (nodeId applies to fills and is not for SVG).

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