Fusion360 MCP Server

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

Annotations indicate the tool is not read-only, idempotent, or destructive, but the description adds minimal behavioral context. It does not explain what extrusion entails (e.g., creating new geometry, modifying existing bodies based on the 'operation' parameter), potential side effects, or performance considerations. While not contradicting annotations, the description fails to provide meaningful behavioral insights beyond the basic action.

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 extremely concise—a single phrase—with no wasted words. It is front-loaded and efficiently states the core action, though this brevity contributes to gaps in other dimensions. Every word earns its place by directly addressing the tool's function.

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?

Given the tool's complexity (4 parameters, including enums for 'operation' and 'direction'), lack of output schema, and minimal annotations, the description is incomplete. It does not cover parameter meanings, expected outcomes, or integration with sibling tools, leaving significant gaps for an agent to understand and use the tool effectively in a 3D modeling context.

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?

With 0% schema description coverage, the input schema lacks parameter explanations, and the description does not compensate by detailing any parameters. It mentions 'sketch profile' but does not clarify how parameters like 'height', 'profile_index', 'operation', or 'direction' affect the extrusion process. This leaves key semantics undocumented, failing to add value beyond the bare 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?

The description 'Extrude a sketch profile' clearly states the action (extrude) and target (sketch profile), providing a basic understanding of the tool's function. However, it lacks specificity about what extrusion does (e.g., creating 3D geometry from 2D profiles) and does not distinguish it from similar sibling tools like 'revolve', 'sweep', or 'loft', which also create 3D geometry from sketches. This makes the purpose somewhat vague in context.

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 provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., needing an existing sketch), compare it to sibling tools like 'revolve' or 'sweep' for different 3D modeling approaches, or specify scenarios where extrusion is preferred. This absence of usage context leaves the agent without direction on tool selection.

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