create_sketch

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

The description discloses that the sketch is left in EDIT mode after creation, and returns the sketch name and resolved plane name. With no annotations, it carries full burden; some minor aspects like error handling on invalid plane names are not covered, but overall it's good.

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 concise and well-structured: one sentence for purpose, a bullet list for parameter values, and clear flow instructions. Every sentence adds value without redundancy.

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 or annotations, the description covers input, behavior (edit mode), return values, prerequisites, and post-creation steps. It is sufficiently complete for an agent to use correctly.

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%, but the description fully explains the plane_name parameter: lists valid values ('front', 'top', 'right' and Spanish equivalents) and notes case-sensitivity. This adds complete meaning beyond the schema that only defines type 'string'.

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' with specific verb and resource. Among siblings like create_sketch_on_face, it correctly distinguishes by specifying the starting reference is a plane, not 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 when to use (requires a part document, not assembly) and provides a workflow sequence: create_sketch first, then add geometry with create_rectangle, then extrude_sketch. It also warns about the prerequisite of opening a fresh part.

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