create_color_variable

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals the key upsert behavior: 'If the variable exists, its value for the default mode is updated.' This is a critical behavioral trait beyond simple create/update. However, it does not disclose details about collection creation or potential side effects on other modes, so it's not a 5.

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 two sentences, front-loaded with the core action, and contains no redundant information. Every word earns its place, making it highly concise and well-structured.

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 six parameters and no output schema, the description is adequate: it states the core function, the update behavior, and the scope (default mode). The schema covers parameter details. However, it misses explicit guidance on when to use this over sibling tools, and does not mention collection creation behavior, which is only in the schema. Still, it is reasonably complete for a simple 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%, with each parameter (r, g, b, a, name, collectionName) already documented in the input schema. The description adds no parameter-specific meaning beyond implying color values affect the default mode. Per the baseline rule, a score of 3 is appropriate when the schema already provides full parameter documentation.

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's function: 'Create or update a single Figma color variable.' This is a specific verb-resource combination, and the word 'single' distinguishes it from sibling tools like create_multiple_color_variables. It also adds the update behavior for existing variables, which is unambiguous.

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 usage for single color variable creation/update, but it does not explicitly mention when to prefer this over alternatives like create_multiple_color_variables or create_paint_style. There is no explicit context for when-not-to-use or alternative tool names, so the guidance is only implied.

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