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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the agent knows this is a mutating, overwriting operation. The description adds the field semantics but nothing about scope (which page), persistence, permissions, or that existing spacing values are replaced.

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?

Two short sentences, front-loaded with the concept and then the field mapping. No filler, though it is perhaps a touch too terse given the missing scope detail.

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 destructive write tool with no output schema and 0% schema coverage, the description explains the two enum fields but omits the required projectId's role and the scope of the change. Adequate but with clear gaps.

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 carry parameter meaning, and it does: sectionY is the padding between sections and sectionX the side gutter. That covers 2 of 3 params meaningfully; only projectId, which is required and scopes the write, goes unexplained.

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 (the page's vertical rhythm / side gutter, i.e. the Spacing control) and disambiguates the two main fields, so the agent can tell what is being configured. The verb is only implied by the tool name, and nothing distinguishes it from sibling setters like set_section_style or set_type_scale.

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?

There is no when-to-use guidance, no mention of prerequisites (e.g. that a project/page must already exist), and no routing to or away from alternatives. The agent gets no signal about when spacing should be set versus left alone.

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