create_sketch

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

No annotations are provided, so the description bears full responsibility. It discloses that the sketch is left in 'EDIT mode', returns the sketch name and resolved plane name, and includes important caveats about document type.

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 efficiently structured: purpose first, then argument details, then return value, then caveat. Every sentence adds value; no redundant 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?

For a single-parameter tool with no output schema, the description fully explains the return values, post-conditions (EDIT mode), and necessary context (part document). It also mentions subsequent steps, making the tool's role in a workflow clear.

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?

The input schema has 0% description coverage for plane_name. The description adds extensive detail: lists the allowed values (front/top/right, plus Spanish equivalents), notes case sensitivity, and specifies lowercase English. This fully compensates for the schema 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 clearly states 'Start a new sketch on a named reference plane.' It uses a specific verb ('Start') and resource ('sketch on named reference plane'), distinguishing it from similar tools like create_sketch_on_face which creates on a face.

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 explicitly states the prerequisite: 'requires a part document (not assembly). Open a fresh part via SW UI before calling.' It also provides a sequence of use: create_sketch -> create_rectangle -> extrude_sketch, giving clear when-to-use guidance.

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