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

Annotations declare destructiveHint=true and readOnlyHint=false, so the safety profile is known. But the description never states that existing spacing settings will be overwritten, whether changes are reversible, or what happens to unspecified spacing keys — gaps that matter for a destructive setter.

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 dense sentence with no filler, front-loading the core concept before defining each parameter. It is slightly long but every clause carries parameter meaning.

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 four-parameter destructive mutation with no output schema, the description covers the three spacing options well but omits prerequisites, default behavior for omitted parameters, and confirmation of effect on existing settings. Annotations carry the safety burden, but the description could do more for a mutating tool.

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 0%, so the description must compensate. It does explain all three optional parameters in domain terms: sectionY as padding between sections, sectionX as side gutter, and gridGap as space between grid items, including the multiplier semantics (tight=0.6x, roomy=1.5x) that the schema's enum values don't convey.

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 identifies the resource precisely (vertical rhythm, side gutter, grid gap) and maps to the Spacing control, so an agent can tell it adjusts page spacing. It does not explicitly say 'sets' or differentiate from siblings like set_theme or set_type_scale, relying on the tool name for the verb.

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 on when to use this tool versus alternatives such as set_theme or set_section_style, nor any prerequisites beyond the schema. The description is purely explanatory about parameters.

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