AutoCAD MCP Native Bridge

by Yimmingyang

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draw_circle

Create a circle in AutoCAD model space by specifying center XYZ coordinates and a positive radius in drawing units.

Instructions

Draw a circle in model space using center XYZ coordinates and positive radius in drawing units.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "center": "<center>",
      "radius": "<radius>"
    },
    "name": "draw_circle"
  }
}

Input Schema

Name	Required	Description	Default
`center`	Yes
`radius`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.6.0Oct 21, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations, the description carries the full behavioral burden. It discloses the unit semantics ('drawing units') and radius constraint ('positive'), but says nothing about which drawing is mutated, whether the new entity is returned, what layer it lands on, or whether the operation is undoable.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence that states the action, the geometry target, and the parameter semantics without any filler. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutating geometry tool with zero annotation coverage, no output schema, and 0% schema description coverage, the description omits key context an agent needs: the affected drawing, return value, layer assignment, and failure conditions. It is under-specified relative to the tool's complexity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate, and it partly does: it maps 'center' to XYZ coordinates and 'radius' to a positive value in drawing units, aligning with exclusiveMinimum 0. It does not explain that z is optional or what default is applied when omitted, a real gap given the nested object.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

Names a specific verb and resource ('Draw a circle') plus the target space ('model space'), so the operation is unambiguous. However it does nothing to distinguish this from the many sibling draw primitives (draw_line, draw_polyline, draw_rectangle), leaving the agent to infer the difference from the name alone.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no when-to-use, when-not-to-use, or alternative guidance. It never states the prerequisite that a drawing must be open/active (siblings like open_drawing and get_active_drawing exist), nor when a circle is preferable to other shape primitives.

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