chamfer

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

Annotations already declare non-readonly, non-destructive, non-idempotent, so the safety profile is covered. The description adds genuinely useful behavioral detail beyond that: it discloses the precedence rule (distance2_mm > 0 overrides angle_deg) and what 'flip' changes, which is exactly the kind of interaction an agent needs.

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?

Front-loaded with the core verb, then compact parameter rules with no filler. The second sentence is dense and runs several clauses together, but every clause carries information.

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?

With annotations and an output schema present, the description covers the operation and its mode-selection logic adequately for a multi-mode feature tool. Minor gaps remain around edge/face point selection and document context, but nothing that would cause a wrong call.

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 50%, so the description must compensate, and it does for the key numeric parameters: angle default 45 meaning equal sides, distance2_mm switching to a two-distance mode, and flip's effect. edge_points/face_points are only deferred by reference ('as for fillet'), leaving their selection semantics dependent on the sibling's documentation.

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 opening 'Bevels edges' states a specific operation on a specific entity, and the rest of the description clarifies the geometric meaning of the chamfer parameters. It does not explicitly contrast with the sibling 'fillet' (which rounds rather than bevels), so an agent must infer that distinction, but the verb+resource are unambiguous.

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 through parameter behavior ('Default: distance_mm at angle_deg', 'With distance2_mm > 0 ...'), which tells the agent which mode to pick, but there is no explicit when-to-use/when-not guidance and no mention of prerequisites such as an active part or a selected edge.

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