fusion_sketch_arc

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

Annotations indicate it is not read-only (writes to sketch) and open world (may create new entities). Description adds that it draws in mm and is a 3-point arc, but does not disclose behavior on invalid geometry (e.g., collinear points) or whether it modifies the current sketch.

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 very concise (two short sentences), front-loading the action. However, it could be more structured (e.g., listing parameters) to improve readability.

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 no output schema and simple annotations, the description is adequate for basic usage but lacks details on error handling, return values, and the relationship to the sketch context.

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 description must compensate. It explains the six required parameters (x1,y1 as start, x2,y2 as through, x3,y3 as end) but does not explain the optional 'plane' and 'sketch' parameters, leaving their purpose unclear.

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 explicitly says 'Draw a 3-point arc' with specific coordinate parameters (x1,y1,x2,y2,x3,y3), clearly distinguishing it from sibling sketch tools like fusion_sketch_line or fusion_sketch_circle. It also specifies units (mm).

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 mentions it is 'Useful as a sweep/revolve path,' giving a use case, but does not explicitly state when to use this tool versus alternatives (e.g., other arc types) or 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.