add_text_on_face

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

With no annotations, the description carries the full burden and does well: it discloses the per-face orientation behavior, the font-installed prerequisite, and the return value (text_area_mm2). It omits permission/error behavior and mutation reversibility, but for a local CAD modeling op this is strong disclosure.

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 verb and use case, and each sentence carries real information. The orientation clause is dense but earns its place by preventing misplacement; minor redundancy between the corner and 'two dimensions' phrasing costs a point.

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?

No output schema exists, yet the description supplies the return value, and for a 10-param tool at 0% schema coverage it documents most semantics plus orientation behavior. The undocumented face/name parameters and the z-axis ambiguity are the only material 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 0%, so the description must compensate and does explain x/y/z, height_mm, depth_mm, emboss and font semantics. However it leaves 'face' and 'name' undocumented and introduces confusion by first describing a three-coordinate corner then stating 'the position is two dimensions ('x','y')' while z_mm is required.

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 ('Engrave text into ANY planar face, or emboss it') that an agent can distinguish from every sibling, none of which touch face text. The parenthetical use case (labels, version numbers) sharpens intent further.

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 when-to-use guidance by explaining which faces yield readable text ('put labels on the top or front') and how the emboss=True variant is selected. No explicit alternatives are named, but no sibling overlaps this operation, so the practical routing advice is the useful part and it is present.

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