set_layout_sizing

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

There are no annotations, so the description carries the burden of disclosing behavioral traits. It does not mention side effects, constraints, error handling, or what happens if the target node is not an auto-layout frame. The only hint is that the target is an auto-layout frame, but this is more a target description than a behavioral disclosure.

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?

A single, compact sentence that conveys the tool's purpose without extraneous details. It is well-structured and front-loaded, making it easy for an agent to quickly understand the action.

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 a simple setter with 3 well-described parameters and no output schema. The description is adequate for basic use but lacks details about failure modes, prerequisites (e.g., node must be an auto-layout frame), or interactions with other layout settings. Given the simplicity, it meets the minimum viable threshold.

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 fully described (nodeId, layoutSizingVertical, layoutSizingHorizontal) including enum constraints and special conditions (e.g., HUG for frames/text only, FILL for auto-layout children). The description adds no additional parameter semantics beyond what the schema already provides, 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?

The description clearly states the action ('Set') and the resource ('horizontal and vertical sizing modes for an auto-layout frame in Figma'). This distinguishes it from sibling tools like set_layout_mode, which focuses on layout direction rather than sizing modes. The mention of both horizontal and vertical adds specificity.

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?

No guidance is provided about when to use this tool versus alternatives. It does not mention that this is specifically for auto-layout frames (though implied) or that it complements set_layout_mode or set_padding. No exclusions or alternative tool mentions exist.

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