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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint. The description adds the return format (map of node ids to URLs) but does not elaborate beyond that. No contradiction with annotations.

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?

Two sentences with no extraneous information. The first sentence defines the core action, the second clarifies usage and output formats. Front-loaded and efficient.

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 4-parameter tool with no output schema, the description explains the return type and format options. However, it could be more explicit about the map structure and the comma-separated format for node IDs (though captured in schema). Adequate for the complexity.

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 the schema already fully documents parameters. The description adds a brief mention of output formats (PNG, SVG, JPG) but does not provide meaningful additional semantics beyond what the schema offers.

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 states the tool renders images of specific Figma nodes and returns a map of node IDs to image URLs. It uses a specific verb ('Render') and resource ('images of specific nodes'), and the mention of 'visual previews' distinguishes it from sibling tools like get_file_nodes that retrieve node data.

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 says 'Use to get visual previews...', implying when to use, but does not explicitly exclude alternatives or name sibling tools. However, the context of the design file and the distinction from data retrieval tools is clear enough.

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