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

Annotations already declare readOnlyHint and idempotentHint, and the description complements this by explicitly stating the tool does NOT download the file, only returns the URL. This adds behavioral context beyond the annotations, though it does not mention error handling or invalid slugs.

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 two sentences with no wasted words; the first sentence states the core function, and the second clarifies the non-downloading behavior. It is front-loaded with the purpose and remains highly concise.

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 tool with one parameter and strong annotations, the description covers the return value, contents of the ZIP, and the distinction between returning and downloading. It is complete enough for an agent to select and invoke correctly.

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?

The input schema fully describes the 'slug' parameter with an example ('inter'), and the description references 'font family' but does not add extra meaning beyond the schema. Since schema coverage is 100%, the baseline of 3 applies.

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 states the tool returns a direct ZIP download URL for a font family, using a specific verb ('Return') and resource. It also distinguishes from sibling tools by noting it does not download and includes a ready fonts.css, differentiating it from get_font_files or get_fonts_css.

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 description implies the tool is used when the user needs a download link rather than actual file content, advising to hand the URL to the user or fetch separately. It does not explicitly name alternatives, but the usage context is clear and actionable.

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