set_item_spacing

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the basic action but does not mention potential side effects, error conditions (e.g., if the frame is not auto-layout), or any interaction with other layout properties like primaryAxisAlignItems. This leaves significant behavioral aspects undisclosed.

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 sentence that front-loads the verb and resource, with no extraneous words or repetition. Every word 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 setter with two fully-documented parameters and no output schema, the description covers the essential purpose. The schema already provides detailed parameter notes (e.g., the SPACE_BETWEEN interaction), so the description does not need to repeat them. It lacks only minor context about preconditions or failure behavior, which would push it to a 5.

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 both nodeId and itemSpacing fully described in the schema. The description's phrase 'distance between children' paraphrases itemSpacing but adds no additional semantic value beyond the schema. The baseline of 3 is appropriate since 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 uses a specific verb ('Set') and clearly identifies the resource ('distance between children in an auto-layout frame'). It distinguishes itself from sibling tools like set_padding or set_axis_align by targeting the item spacing property specifically.

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' implies the tool applies only to auto-layout frames, giving some context. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites.

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