add_chamfer

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

With no annotations, the description carries the transparency burden. It discloses the mutating nature ('Chamfer edges of the current part'), the return value, and the dependency on list_edges for edge indices. It stops short of stating side effects such as irreversibility or failure behavior when edges are invalid or exhausted.

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 compact and front-loaded: the core action appears in the first sentence, followed by essential edge-value semantics and the return summary. Every sentence adds useful information with no filler.

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 three-parameter CAD mutation with no output schema, the description covers the required distance, accepted edge selectors, the dependency on list_edges, and what is returned. It lacks only edge-case details such as behavior without an open part or with empty edge selections, which are unlikely to be blockers for correct invocation.

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 the description must compensate, and it does for two of the three parameters: it explains that distance_mm is the chamfer distance in millimeters and fully specifies the edges parameter with 'all', axial shortcuts, and list_edges indices. The optional name parameter is not explained, but it is a minor labeling field with a schema default.

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 uses a specific action ('Chamfer edges') and identifies the exact resource ('the current part'), plus the fixed 45° angle and mm distance. This clearly distinguishes it from sibling operations like add_fillet, so an agent can select it without inspecting the schema.

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 edge-selection paragraph and the reference to list_edges provide practical context for when and how to invoke the tool. However, it does not explicitly state when to prefer this over alternatives such as add_fillet, nor does it state exclusions or prerequisites beyond 'current part.'

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