preview_text

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

Annotations already establish readOnly/idempotent/non-destructive, so the bar is lower. The description adds real context beyond that: box-fitting in mm, '\n' newline semantics, and the caveat that most Hershey names retrace every stem. It stops short of saying what the preview output actually looks like.

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?

Front-loaded with the core operation, then the operational details. The font enumeration is somewhat long but is high-value content rather than filler, so waste is minimal.

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?

Adequate for a preview tool with no output schema, but incomplete: 7 parameters at 0% schema coverage means the description should clarify at least simulate and the optional box coordinates, and it does neither. An agent still has open questions about what the call returns.

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 0%, so the description carries the burden, and it does explain the box semantics (x,y,w,h in mm) and newline handling for text. However, font is only hinted at via face names, and the defaulted simulate flag plus the null-default nature of x/y/w/h are never explained.

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+resource ("Render single-stroke (Hershey) text fitted into box") and clarifies units (mm) and newline handling. It does not, however, distinguish itself from the sibling draw_text, leaving the preview-vs-draw distinction to inference.

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?

Gives concrete guidance on font selection (prefer handwriting faces, with named examples) and points to list_fonts() for measurements, which is useful. But it never says when to choose preview_text over the sibling draw_text or preview_svg, and the simulate parameter's role is left unaddressed.

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