AutoCAD MCP Native Bridge

by Yimmingyang

Overview Schema Source Related Servers Discussions Admin

Local

open_drawing

Open an existing DWG in AutoCAD through the bridge. Set readOnly to true to prevent modifications.

Instructions

Open an existing DWG in AutoCAD through the bridge. Set readOnly to true to prevent modifications.

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": {
      "path": "<path>"
    },
    "name": "open_drawing"
  }
}

Input Schema

Name	Required	Description	Default
`path`	Yes
`readOnly`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.6.0Oct 21, 2026

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations, the description carries the full behavioral burden, and it does disclose the one genuinely useful trait: readOnly=true suppresses modifications. It is silent on side effects an agent needs — whether opening replaces the currently active drawing, what happens if the file is missing or already open, and whether the bridge must be running.

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?

Two sentences, no filler, with the core action front-loaded and the one non-obvious parameter fact placed second. Every clause earns its place.

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

Completeness3/5

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

For a two-parameter tool with no output schema, the description covers the action and the readOnly flag but omits the state implications of opening a drawing (displacing the active document) and any failure modes. Adequate but noticeably thin for a state-changing operation with zero annotation support.

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% and there are two parameters, so the description must compensate. It explains readOnly meaningfully ("prevent modifications") but gives nothing on `path` — no format, whether it is local or bridge-side, or whether a full path is required beyond minLength 1.

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?

States a specific verb and resource ("Open an existing DWG in AutoCAD") plus the transport mechanism ("through the bridge"). This is enough to separate it from create_drawing_copy and get_active_drawing, though it never names a sibling explicitly, so a 4 rather than a 5.

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

Usage Guidelines3/5

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

Usage is only implied: the word "existing" tells the agent this is for files that already exist, so a copy-creation sibling is the wrong choice. There is no explicit when-not guidance, no prerequisite (e.g., must the bridge be connected), and no named alternative.

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