set_item_spacing

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

With no annotations, the description carries the full burden for behavioral disclosure. It states the action but does not disclose prerequisites (frame must be auto-layout), side effects (children repositioned), or error behavior if conditions are not met. The schema notes about ignored values are helpful but exist outside the description, so the description itself lacks transparency.

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, focused sentence that is front-loaded with the verb and resource. No wasted words, easily scannable, and appropriately sized for a simple setter tool.

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 mutation with 3 well-documented parameters and no output schema, the description plus schema is largely complete. It could mention what happens if the frame is not auto-layout or return value expectations, but the current information is sufficient for basic usage.

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%, and each parameter has a detailed description including conditional notes (itemSpacing ignored with SPACE_BETWEEN, counterAxisSpacing works only with WRAP). The tool description adds no additional parameter-level meaning, 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 'Set distance between children in an auto-layout frame' uses a specific verb ('Set') and resource ('distance between children') with a clear scope ('auto-layout frame'). It clearly distinguishes this tool from sibling set_* tools like set_padding or set_axis_align by focusing specifically on spacing.

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 phrase 'in an auto-layout frame' provides clear context for when this tool is applicable, implying it should be used only for auto-layout frames. However, it does not explicitly mention alternatives or exclusions, though the schema notes about SPACE_BETWEEN and WRAP add conditional guidance.

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