Fusion360 MCP Server

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

Annotations already indicate this is a mutable operation (readOnlyHint: false) that's neither idempotent nor destructive. The description adds some context about being 'non-parametric via TemporaryBRepManager', which suggests a specific creation method, but doesn't elaborate on what this means behaviorally (e.g., whether the sphere can be edited later, if it's temporary, or how it integrates with the CAD environment).

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 gets straight to the point. It could potentially benefit from slightly more context about the sphere's characteristics or usage, but it doesn't waste words and communicates the core purpose effectively.

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 no output schema and minimal annotations beyond basic mutability hints, the description provides the essential 'what' but lacks important context. It doesn't explain what happens after creation (e.g., where the sphere appears, whether it's selectable/editable, or what the return value might be). The 'non-parametric via TemporaryBRepManager' hint suggests technical specifics but doesn't make them actionable for an AI agent.

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 schema provides only basic type constraints. The description doesn't add any parameter information beyond what's implied by the tool name. It doesn't explain what 'radius' represents, what units are used, or what the center coordinates mean in the 3D space. However, the parameter names are self-explanatory (radius, center_x/y/z), providing some inherent clarity.

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 verb ('Create') and resource ('sphere primitive'), specifying it's non-parametric via TemporaryBRepManager. However, it doesn't explicitly differentiate from sibling tools like 'create_box' or 'create_cylinder' beyond the sphere shape, leaving some ambiguity about when to choose this specific primitive creation tool.

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?

No guidance is provided on when to use this tool versus alternatives like 'create_box' or 'create_cylinder'. The description mentions 'non-parametric via TemporaryBRepManager', but doesn't explain what this means in practical usage or when this approach is preferred over parametric alternatives.

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