mate_coincident

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

With no annotations and no output schema, the description carries the full behavioral burden but provides almost no disclosure: it does not explain what a coincident mate does, what constitutes a valid reference, whether the operation is destructive or reversible, or what prerequisites (e.g., an open assembly) are required. It only implies a mutation operation.

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 with no wasted words, which is efficient. However, given the tool's 8 parameters and complex domain, it is too brief to be considered appropriately sized, so it earns a middle score.

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?

No annotations, no output schema, and 0% parameter description coverage make this description drastically incomplete. An agent lacks the information needed to correctly choose between this and sibling mates or to supply the required reference parameters, so it cannot be called complete.

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% across 8 parameters, and the description does not clarify the meaning of a, b, face_a, face_b, axis_a, axis_b, value, or assembly_id. The phrase 'two references' vaguely maps to a and b, but leaves the remaining six parameters entirely undocumented, failing to compensate for the coverage gap.

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 ('Create') and resource ('coincident mate between two references'), which clearly distinguishes it from mate_concentric, mate_distance, mate_angle, and mate_parallel. However, it does not differentiate from the similarly named add_constraint_coincident (a sketch-level constraint) or explain the reference types, so it falls short of a 5.

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?

No guidance on when to use this assembly mate versus other mate types (e.g., mate_concentric, mate_distance) or the sketch constraint add_constraint_coincident. The description only states what it does, leaving the agent to infer context and prerequisites entirely.

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