Fusion360 MCP Server

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

Annotations indicate this is a non-read-only, non-idempotent, non-destructive operation. The description adds useful context about units (cm for distances, degrees for angles) which isn't in the annotations. However, it doesn't disclose other behavioral traits like whether dimensions are editable after creation, if they affect sketch regeneration, or error conditions. With annotations covering basic safety, this adds some value but not rich behavioral context.

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 perfectly concise with two clear sentences. The first states the core purpose, the second provides crucial unit information. Every word earns its place with zero wasted text, 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 tool with 5 parameters, 80% schema coverage, and no output schema, the description provides adequate but incomplete context. It covers the purpose and units well, but doesn't explain the tool's role in the sketching workflow, how dimensions interact with constraints, or what happens after dimension addition. Given the complexity and lack of output schema, more context would be beneficial.

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 80%, so the schema already documents most parameters well. The description adds unit information (cm/degrees) for the 'value' parameter, which provides helpful semantic context beyond the schema's numeric type. However, it doesn't explain the relationship between 'dimension_type' choices and other parameters (e.g., when 'entity_two' is required), leaving some gaps.

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 tool's purpose: 'Add a driving dimension to constrain sketch geometry.' It specifies the action (add), resource (driving dimension), and context (sketch geometry). However, it doesn't explicitly differentiate from sibling tools like 'add_constraint' or 'create_sketch', which would be needed for a perfect score.

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 doesn't mention when to choose this over 'add_constraint' or how it relates to 'create_sketch' or other geometry tools. Without any usage context or exclusions, this is minimal guidance.

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