upload_assets

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

With no annotations present, the description carries the full burden and does a good job by disclosing supported formats, single-use URLs, the need to POST raw bytes, and the expected output shape. It does not mention authentication requirements or side effects on the Figma file, but the core behavioral contract is clearly stated.

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 compact, front-loaded with the purpose, and every sentence carries useful information: formats, return URLs, the follow-up POST action, and the expected output. There is no filler or redundancy.

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 no annotations and no output schema, the description provides the crucial output contract and workflow. Still, it omits context such as authentication prerequisites, how fileKey relates to the target file, the meaning of scaleMode, and whether providing nodeIds immediately mutates fills.

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 60%, and the description adds no direct parameter-level meaning. The required fileKey and the scaleMode parameter are left undocumented in both the schema and the description, and there is no explanation of how count or nodeIds map to the upload workflow.

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 clearly identifies the action: 'Uploads images (PNG, JPG, GIF, WebP) or SVGs into a Figma file.' It also names the output behavior and separates this tool from siblings like download_assets by specifying the upload direction and exact workflow.

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 description implies when to use the tool: whenever images or SVGs need to be uploaded into Figma. However, it gives no explicit when/when-not guidance or alternatives, such as mentioning download_assets for retrieval or use_figma for broader operations.

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