figma_create_variable_collection

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 usefully discloses that the resulting collection is empty and the plugin requirement, but says nothing about duplicate-name handling, whether modes are auto-created, or what identity is returned for the new collection.

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 tight sentences. The core action and the 'empty' constraint come first, the alternative routing second, and the plugin prerequisite last — every clause 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?

For a simple 3-parameter creation tool with full schema coverage and no output schema, the description covers action, scope, alternative, and prerequisite. The remaining gap is mutation behavior (collision handling, confirmation of created mode names), which no structured field covers.

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 all three parameters (name, additionalModes, initialModeName) are already documented with examples. The description adds no syntax or constraint detail beyond the schema, so the baseline 3 applies.

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?

Specific verb+resource ('Create an empty variable collection') with a scope qualifier ('empty') that distinguishes it from the batch/setup path. It also names the sibling it is not, so the agent can differentiate without opening schemas.

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 routes the agent: use figma_setup_design_tokens when variables and modes are needed in one step, otherwise this tool. The runtime prerequisite ('Requires Desktop Bridge plugin') is stated up front so the agent knows the invocation precondition.

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