new_row

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

The description discloses key behavioral traits: responsive auto-collapse with default tablet/mobile breakpoints, and the fact that it returns a node to be placed inside a section. However, it does not mention permissions, side effects, or return format details, which are less critical for a builder tool.

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 well-structured: starts with the core purpose, then use cases, then responsive behavior, then nesting guidance, and ends with an example. Each sentence adds value, and the content is front-loaded for quick scanning.

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?

Given the tool's complexity (6 parameters, nested objects, no output schema), the description provides sufficient context: it explains the row vs. column distinction, responsive behavior, placement within a section, and includes an example. It does not explicitly detail the return value beyond mentioning the returned node, but this is a minor omission because the schema describes the parameters.

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 already covers all 6 parameters with descriptions (100% coverage), so the baseline is 3. The description adds a concrete example of the children array and clarifies the responsive behavior, which helps the agent understand how parameters like collapse and column_gap work in practice.

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 identifies the tool as a multi-column row container with children laid out side by side. It distinguishes itself from stacked sections and provides specific use cases like feature cards, category tiles, and footer columns, making the purpose 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?

Explicitly explains when to use the row (for horizontal layouts) and when not to (sections stack vertically), and instructs to place the returned node as a child inside a section. Also gives concrete examples of real-page use cases, effectively guiding the agent's tool selection.

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