figma_update_variable

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

Annotations already mark the tool as destructive (destructiveHint: true). The description adds no further behavioral context beyond the update action, such as whether changes are reversible or impact other modes. It neither contradicts nor significantly extends the 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?

Extremely concise: two sentences conveying the action and a key prerequisite. No redundant information. Every part earns its place.

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 (3 required params, no output schema, destructive), the description provides the core action and a prerequisite but omits parameter semantics and return value details. It is adequate but not comprehensive.

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?

The input schema has 0% description coverage for parameters, and the description does not explain individual parameters (variableId, modeId, value). While it implies modeId refers to a mode, it lacks details on how to specify values across different types (string, number, boolean). The description should compensate but falls short.

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?

Clearly states the action 'Update a variable value in a mode', specifying both the resource (variable) and scope (mode). Distinguishes from siblings like figma_create_variable (create) and figma_batch_update_variables (batch) by focusing on single update.

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?

Provides a clear prerequisite: 'Get IDs from figma_get_variables.' This guides the agent to obtain necessary inputs. However, it does not explicitly mention when to use this tool over alternatives like figma_batch_update_variables, leaving some ambiguity.

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