create_polygonDraw a regular polygon in the most recent Fusion 360 sketch by setting side count, circumradius, and optional center coordinates in centimeters.
Draw a regular polygon in the most recent sketch. Unless a parameter says otherwise, lengths and coordinates are in cm (not mm) and angles in degrees.
| Name | Required | Description | Default |
|---|---|---|---|
| sides | Yes | ||
| radius | Yes | Circumradius (cm) | |
| center_x | No | ||
| center_y | No | ||
| center_z | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the mutation profile is covered by structured data. The description adds real value by disclosing the 'most recent sketch' target and the cm/degree unit convention, but omits what happens if no sketch is active and whether it creates geometry non-idempotently.
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?
Two short sentences, front-loaded with the action and target; the unit caveat is appropriately placed at the end. No filler, though the second sentence is a generic caveat rather than parameter-specific detail.
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 creation tool with no output schema and low schema coverage, the description covers target context and units but leaves the sketch prerequisite, failure modes, and most parameter semantics undocumented.
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 only 20% (just radius), so the description must compensate. It does partly by stating that lengths and coordinates default to cm and angles to degrees, which clarifies center_x/y/z and radius, but 'sides' and the center point meaning remain unexplained beyond the schema.
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 specific verb (Draw) and resource (regular polygon) plus the target location ('most recent sketch'). This cleanly distinguishes it from draw_rectangle, draw_circle, and draw_line by resource name, though it does not name those siblings explicitly.
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?
There is no when-to-use/when-not guidance and no mention of alternatives such as draw_circle (a polygon as a many-sided alternative) or the requirement that a sketch must already exist. Only the unit convention is supplied, which is not usage guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.