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

Annotations already flag destructiveHint=true and readOnlyHint=false. The description goes beyond them by disclosing the scope of mutation on imported projects: only the changed control is applied and body face/weight/case/tracking are left intact. That is genuinely useful side-effect context, though it still doesn't fully explain what 'destructive' means for a fresh (non-imported) project.

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 sentences, front-loaded with the action and followed by the imported-project caveat. Nothing is padded, though the second sentence is dense and could be split for readability.

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 3-param destructive mutation with no output schema, the description covers the important imported-project behavior but leaves the default (new project) behavior, parameter formats, and return/confirmation behavior unaddressed. 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 coverage is only 33% — just the heading param is documented ('A Google Font family name'). The description clarifies that heading and body are the two independent axes being set, adding meaning over the bare schema, but it does not explain what body accepts (same Google Font family format?) or what projectId selects.

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?

States a specific verb and resource: 'Set the heading and/or body font.' An agent can distinguish this from nearby siblings like set_type_scale (scale, not face) or set_text_style. It stops short of naming an alternative, but the resource is precise.

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 second sentence gives real context about how the change applies on imported projects, which helps an agent decide whether this call is safe. However, there is no explicit when-to-use / when-not guidance relative to set_type_scale, set_theme, or set_text_style, so routing is left to inference.

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