figma_create_variable

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

With no annotations, the description carries the full burden. It only states that it uses the REST API and doesn't require a plugin, but fails to disclose prerequisites, side effects, or response behavior. This is minimal transparency for a mutation tool.

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 a single sentence, front-loaded with the core purpose, and contains no waste. However, it is brief to the point of underspecification, so it does not earn a 5.

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?

Given the tool's complexity (8 parameters, nested objects, no output schema) and low schema coverage, the description is severely incomplete. It fails to explain where to find the fileKey and collectionId, how to format values, or what the response contains.

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 only 38%, so the description should compensate by explaining parameters. However, it only repeats the enum values already present in the schema, adding no meaning for parameters like collectionId, name, value, scopes, or valuesByMode.

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 action ('Create a variable') and lists the allowed types (COLOR, FLOAT, STRING, BOOLEAN). It distinguishes from sibling tools like create_variable_collection by focusing on the variable resource, though it doesn't explicitly mention that a collection ID is required.

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?

No guidance is provided on when to use this tool versus alternatives like update_variable or set_variable_value. The note 'Uses REST API — no plugin required' is a technical detail, not usage guidance.

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