set_layout_sizing

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

With no annotations provided, the description carries full burden for behavioral disclosure. It merely states the action without noting constraints, side effects, or failure modes, such as what happens if the target node is not an auto-layout frame or if an invalid sizing mode is supplied. This is a mutation tool, so more transparency is expected.

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 that directly states the action and target. Every word earns its place with no redundant information, making it optimally concise.

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?

The tool is simple (3 params, no output schema) and the description defines its scope clearly. It could optionally mention that the node must already be an auto-layout frame, but this is implied by the phrase 'auto-layout frame'. Given the simplicity and strong schema coverage, the description is sufficiently complete.

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 schema covers 100% of parameters with descriptions, including enum constraints and usage notes like 'HUG for frames/text only, FILL for auto-layout children only'. The description adds no additional parameter semantics beyond what the schema already provides, so the baseline of 3 is appropriate.

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 uses the specific verb 'set' with a clear resource: 'horizontal and vertical sizing modes for an auto-layout frame in Figma'. This immediately distinguishes it from sibling tools like set_layout_mode (which sets overall layout direction) and set_padding, making the tool's function 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?

It clearly indicates the tool applies to auto-layout frames, which narrows usage context. However, it does not explicitly state when to prefer this over alternatives or mention exclusions (e.g., when the node is not an auto-layout frame), stopping short of full guidance.

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