list_planar_facets

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

With no annotations provided, the description carries the full burden. It implies a read-only operation ('List') and describes output fields, but it does not explicitly state that the tool only reads data, nor does it explain the threshold behavior implied by 'large enough to matter' (likely tied to the min_area parameter). The description adds some value but leaves room for interpretation.

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 a single, front-loaded sentence that gets straight to the point. It includes some illustrative examples of flat faces (top/bottom/side walls, bosses, counterbore floors) that add context without being overly verbose. It is concise but not perfectly 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?

The tool has an output schema and moderate complexity, so the description need not detail return values, but it does mention them (normal, area, footprint size). It lacks specifics about the min_area parameter, how coplanar groups are defined, and any prerequisites or error conditions. Adequate for a simple listing tool but with notable 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 description coverage is 0%, so the description must compensate. It only vaguely references 'large enough to matter,' which hints at min_area but does not clarify its purpose, units, or effect on results. file_path is self-explanatory, but min_area needs more explanation. The description does not adequately cover the parameters.

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 lists coplanar face groups (flat regions) and provides their normal, area, and in-plane footprint size. This distinguishes it from sibling tools like 'find_circular_faces' or 'get_cross_section' by focusing specifically on planar regions. The addition of a use case (spotting sketch planes) further clarifies its purpose.

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 gives explicit context for when to use the tool: 'useful for spotting the flat faces that become sketch planes.' It also hints at the type of output (normal, area, footprint size) that helps an agent decide if this is the right tool. However, it does not mention alternatives or when not to use it, so a small deduction for lacking exclusions.

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