Fusion360 MCP Server

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

Annotations indicate this is a non-readOnly, non-idempotent, non-destructive operation. The description adds that it creates a flange, implying a modeling operation that modifies geometry. However, it doesn't disclose additional behavioral traits like whether it requires specific permissions, how it handles errors, or what the expected output looks like (since no output schema exists).

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 a single, efficient sentence that directly states the tool's purpose without unnecessary words. It is front-loaded with the core action and resource, making it easy to parse quickly.

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 creation tool with 5 parameters, no output schema, and annotations covering basic hints, the description is minimally complete. It specifies the action and target but lacks details on usage context, error handling, or output format, leaving gaps that could hinder effective tool selection and invocation.

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 60% (3 of 5 parameters have descriptions). The description mentions 'on an edge', which hints at 'edge_index', but doesn't add meaning beyond the schema for parameters like 'body_name', 'height', 'angle', or 'bend_radius'. With moderate schema coverage, the baseline score of 3 is appropriate as the description provides minimal additional parameter context.

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 clearly states the specific action ('Create a sheet metal flange') and the target resource ('on an edge'), using precise terminology. It distinguishes this tool from siblings like 'create_bend' (which might create bends without specifying flange geometry) or 'extrude' (which creates features from sketches rather than edges).

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 like 'create_bend' or 'extrude', nor does it mention prerequisites (e.g., needing an existing body with an edge). It simply states what the tool does without contextual usage information.

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