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

Annotations already declare readOnly and idempotent; the description adds value by enumerating the returned metadata fields (styles, weights, axes, license, subsets, download/CSS URLs), giving agents concrete expectations of the response. It does not cover error behavior, but the annotations satisfy the safety profile.

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?

One concise sentence that leads with the verb and resource, then enumerates contents efficiently. No filler or redundancy.

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 simplicity (one param), strong annotations, and a description that explicitly lists the return value categories, the description is complete for an agent to successfully invoke and interpret results. No output schema exists, but the description compensates adequately.

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 single 'slug' parameter is fully described in the schema with an example. The description reinforces 'by slug' but adds no additional syntax, constraints, or formatting details beyond what the schema already provides, so 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 retrieves full metadata for a single font family by slug, listing specific content areas (styles, weights, axes, license, subsets, URLs). This distinguishes it from sibling tools like get_font_files or get_font_download_url, which target narrower subsets.

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 usage context is implied: you need a font slug and want comprehensive metadata. However, it does not explicitly mention when to prefer this over search_fonts or when to use the more specific sibling tools, leaving some ambiguity.

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