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, which the description doesn't contradict. The description adds context about operating on 'the most recent sketch', which is useful behavioral information not covered by annotations. However, it lacks details on potential side effects, error conditions, or what happens if no sketch exists, leaving some gaps in behavioral understanding.

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 with a single sentence that states the core functionality without any wasted words. It's front-loaded with the essential action and context, making it efficient for quick understanding despite its limitations in other dimensions.

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 complexity of a 6-parameter drawing operation with no output schema and 0% schema description coverage, the description is insufficiently complete. It lacks crucial information about parameter semantics, coordinate systems, units, error conditions, and what constitutes 'the most recent sketch'. For a tool that creates geometry in a 3D environment, this leaves significant gaps in understanding how to use it effectively.

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 for all 6 parameters, the description carries full burden for explaining parameter meaning but provides no information about what start_x, start_y, start_z, end_x, end_y, or end_z represent. The description doesn't compensate for the complete lack of parameter documentation in the schema, leaving the agent guessing about coordinate systems, units, or interpretation of these values.

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 action ('Draw a line') and specifies the target ('in the most recent sketch'), which provides a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like 'draw_arc', 'draw_circle', or 'draw_spline' that also draw in sketches, leaving some ambiguity about when to choose this specific drawing 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?

The description provides minimal guidance by specifying 'in the most recent sketch', which implies a prerequisite context but doesn't offer explicit when-to-use instructions or alternatives. There's no mention of when to use this versus other drawing tools (e.g., 'draw_arc' for curves) or how it relates to sibling tools like 'create_sketch', leaving the agent with little 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.