Adjust a Figma node's corner radius to create rounded edges, optionally targeting individual corners for precise shape styling.
Set the corner radius of a node in Figma
| Name | Required | Description | Default |
|---|---|---|---|
| nodeId | Yes | The ID of the node to modify | |
| radius | Yes | Corner radius value | |
| corners | No | Optional array of 4 booleans to specify which corners to round [topLeft, topRight, bottomRight, bottomLeft] |
Changes observed during successful MCP inspections.
v0.3.5Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of disclosing behavioral expectations. 'Set the corner radius' conveys a basic mutation, but it does not mention that the change is persistent, whether unsupported node types will error, how the optional corners parameter interacts with the radius, or whether existing radius values are overwritten. For a mutation tool with no annotation coverage, this is a significant gap.
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, front-loaded sentence with no filler or redundancy. Every word contributes to identifying the tool's action and target. The under-specification of behavioral details is a completeness issue, not a conciseness issue.
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 three-parameter tool with complete schema coverage, the core invocation details are present. However, with no annotations and no output schema, the description leaves important context unstated: how to obtain a valid nodeId, whether all nodes support corner radius, and what happens when corners is omitted. This is adequate but not robust.
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 the schema fully documents nodeId, radius, and the optional corners array. The description adds no parameter-specific meaning beyond echoing the general concept of corner radius. This is the expected baseline when the schema already handles 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 a specific verb ('Set') and resource ('corner radius of a node in Figma'). This meaningfully distinguishes it from sibling tools like set_fill_color, resize_node, or set_padding. Even without a title, the purpose is immediately 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 intended use case is implied by the tool name and description: use it when you need to change a node's corner radius. However, there is no explicit guidance about when not to use it, what node types support corner radius, or how it relates to alternative tools such as resize_node or set_padding. It meets the threshold for implied usage but provides no explicit routing or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.