fillet_edges

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

Annotations already declare that the tool is not read-only, not destructive, and closed-world, so the safety profile is partly covered. The description adds 'constant radius' and the select_edges workflow, but does not disclose that the operation modifies the body geometry, nor does it describe failure behavior or whether the change is reversible.

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 states the operation, the key geometric constraint, and the prerequisite for obtaining edge IDs. No sentence is wasted.

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 presence of an output schema means return values do not need explanation, and annotations cover the safety flags. Still, for a geometry-mutating tool with 0% schema parameter coverage, the missing explanation of 'body' and lack of guidance on invalid or incompatible edges leaves a noticeable gap.

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 carry parameter meaning. It clarifies edge_ids by pointing to select_edges and implicitly clarifies radius as a constant rounding radius, but it does not explain the required 'body' parameter at all.

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 CAD operation: rounding edges with a constant radius. It distinguishes the operation from chamfer by the word 'Round', but does not explicitly name chamfer_edges as the alternative, so it falls short of full sibling differentiation.

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 parenthetical 'get ids from select_edges' gives a useful prerequisite for the edge_ids parameter. However, it does not explain when to use this tool versus chamfer_edges, or mention any limitations such as invalid edge selections or non-fillettable geometry.

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