catia_sketch_arc

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

The description only says 'Add', which implies a mutating operation consistent with readOnlyHint=false. It does not disclose prerequisites (e.g., active sketch, targeting via the 'sketch' parameter), side effects, or error conditions. With annotations providing no behavioral hints, the description carries the full burden but does not deliver.

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?

One concise sentence with zero redundancy. It front-loads the action and immediately provides the defining parameters and angle convention, making it easy to scan and interpret.

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?

For a tool with 6 parameters and no output schema, the description covers the geometric meaning but omits how the target sketch is specified (the 'sketch' parameter) and whether a sketch must be active. It is adequate for a simple geometry operation but leaves some operational context to be inferred.

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 already describes each parameter with units (100% coverage), but the description adds a key semantic: angles are measured counter-clockwise from the sketch's H axis. This convention is not present in the schema and is essential for correct invocation.

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 states a specific verb ('Add') and resource ('circular arc'), with the defining geometry (centre, radius, start/end angles). It clarifies the angle convention (counter-clockwise from H axis), which distinguishes it from siblings like catia_sketch_circle and catia_sketch_ellipse without opening schemas.

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?

Usage is implied: use this when you need a partial circular arc in a sketch. However, it does not explicitly mention when not to use it or compare with alternatives such as catia_sketch_circle for full circles, leaving the selection to inference.

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