catia_face_fillet

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

Annotations already signal readOnly=false and destructive=false, so the mutation status is known. The description adds behavioral context beyond annotations by clarifying the geometric precondition (faces need not share an edge) and the domain (CATIA's Face-Face Fillet). It does not disclose side effects, but this is minor given the annotation coverage.

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 two sentences with no filler. The main action is front-loaded, and the usage guidance follows immediately. Every word earns its place.

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 four simple parameters and no output schema, the description provides enough for selection and invocation: what it does, when to use it, and its distinguishing characteristic. It lacks a note about prerequisite face selection or failure conditions, but these are not essential given the schema and annotation 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 description coverage is 100%, so the parameters first_face, second_face, radius, and name are already documented in the schema. The description adds no parameter-specific semantics beyond the schema, which matches the baseline of 3.

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 ('Round the junction') and resource ('two faces that need not share an edge'), and explicitly names the CATIA Face-Face Fillet feature. It differentiates itself from edge fillet by noting it works where an edge fillet cannot reach, so an agent can distinguish it from sibling fillet tools.

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?

It gives an explicit usage rule: 'Use it where an edge fillet cannot reach, such as across a step.' This tells the agent when to select this tool over an edge fillet alternative and provides a concrete example of the intended scenario.

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