Add a mate

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

Annotations provide only a title, so the description carries full behavioral burden. It never discloses that this is a mutating operation that modifies the assembly by adding a feature, nor does it mention prerequisites like existing mate connectors. 'Join' implies an action but leaves side effects and requirements unspecified.

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?

A single sentence with no filler. The core operation is stated first and the supporting examples follow immediately. Every part 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?

The schema fully documents parameters and the description states the core operation, but with no annotations and no output schema the definition omits behavioral context: it does not say whether this modifies the assembly, what the result is, or what must already exist before calling it. An agent gets the inputs but not enough surrounding context for safe 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 100%, so the baseline is 3. The description adds value by naming concrete mate type values (FASTENED, REVOLUTE, SLIDER, PLANAR) that the schema's 'type' parameter does not enumerate, and it reinforces the minItems=2 requirement for connectors.

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 verb and resource: 'Join two or more mate connectors with a mate.' It clearly distinguishes this tool from the sibling onshape_assembly_mate_connector by focusing on combining existing connectors rather than creating them. The listed mate types further clarify the operation.

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 description gives no explicit guidance on when to use this tool versus alternatives such as onshape_assembly_mate_connector or onshape_assembly_add_feature. There are no exclusions, prerequisites, or routing cues beyond the general implication that it creates a mate.

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