figma_create_variable

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

No annotations are provided, so the description carries the full burden. It does disclose a real operational prerequisite (Desktop Bridge plugin required) and the cross-tool dependency on figma_get_variables, which is valuable. However, it says nothing about mutation semantics such as duplicate-name behavior, whether the variable is created across all modes, or what happens on failure — gaps that matter for an unannotated write 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?

Four short sentences, each carrying distinct actionable information: what it does, when to use the alternative, the prerequisite lookup, and the type surface. No filler and the single-vs-batch distinction is front-loaded.

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?

There is no output schema, and the description never says what is returned (presumably the new variable's ID), which an agent may need for follow-up calls. Otherwise the prerequisites, id source, and supported types make the definition sufficient for a 5-parameter creation tool.

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% and the schema already documents every parameter, including detailed TIMING/EASING formatting and a valuesByMode example, so the baseline is 3. The description's type list ('COLOR, FLOAT, STRING, BOOLEAN, and motion TIMING/EASING') merely restates the enum and adds no syntax or constraint beyond what the schema provides.

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 ('Create a single Figma variable') and immediately scopes it to one variable, distinguishing it from figma_batch_create_variables and figma_create_variable_collection. An agent knows exactly what this does without opening the 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?

Explicitly names the alternative ('use figma_batch_create_variables instead (10-50x faster)'), gives the prerequisite call ('Use figma_get_variables first to get collection IDs'), and states the environmental requirement (Desktop Bridge plugin). All three conditions that gate correct invocation are present.

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