font_build

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

Adds useful behavioral context by stating it does not alter UFO sources and returns persistent paths/hashes. Does not contradict the annotations, though it could mention whether existing build artifacts are overwritten.

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?

Three concise sentences with no fluff; each sentence adds relevant information about behavior, output, and side effects.

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?

Provides output and side-effect context but lacks essential parameter explanations and prerequisites such as requiring an existing project or how revision null is interpreted.

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 schema has three parameters with zero descriptions, and the description does not explain project_id, formats, or revision. 'From a frozen revision' only vaguely hints at the revision parameter.

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?

Clearly states the tool builds TTF/WOFF2 binaries from a frozen revision and returns persistent paths/hashes. This distinguishes it from sibling tools like font_validate and render_glyph.

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?

Implies use when compiled font binaries are needed from a frozen revision, but does not explicitly compare with sibling tools or state when not to use it.

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