add_plane

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

With no annotations, the description carries the full burden and does well: it discloses transform order ('turn first, then offset'), the right-hand-rule convention, and the exact return contents (name, origin_mm, normal, x_axis, y_axis). It stops short of stating side effects on the document or error behavior for invalid inputs.

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 lead sentence front-loads purpose, then details follow. It is dense but each clause (axis conventions, transform order, return formula) earns its place; heavier parenthetical nesting slightly hurts scannability.

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 5-parameter tool with no output schema and no annotations, the description supplies the missing parameter meanings, the return schema, and construction semantics. Only error/edge-case behavior is unaddressed, which is a minor gap for a plane-creation tool.

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%, so the description must compensate, and it largely does: it defines base (front/top/right or a plane by name), offset_mm (distance along the normal), angle_deg (turn amount), and about='x'/'y'/'z' with which axes each base holds. The 'name' input parameter is only referenced obliquely via the return value, leaving mild ambiguity.

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?

States a concrete verb+resource ('Make a reference plane to sketch on') and immediately distinguishes its two construction modes (offset vs. turned). An agent can tell exactly what this builds and how it differs from siblings like add_sketch or add_extruded_profile_on_plane.

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 explains how to configure the two modes in detail, but never states when to choose add_plane over alternatives or the conditions/prerequisites for each mode. Usage is implied rather than prescribed, which is adequate but leaves selection reasoning to the agent.

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