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, covering basic safety. The description adds context about entity referencing by index, which is useful for understanding how to interact with the sketch. However, it lacks details on error conditions, side effects, or what happens if constraints conflict, leaving behavioral gaps.

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 and key operational detail (entity referencing). It is front-loaded with essential information and has no wasted words, making it highly concise and well-structured.

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 moderate complexity (5 parameters, mutation operation) and lack of output schema, the description is adequate but incomplete. It covers the basic action and entity referencing but misses details on usage context, potential errors, or result implications, leaving gaps for an AI agent to infer behavior.

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%, providing good documentation for parameters like 'entity_one' and 'constraint_type'. The description adds minimal value beyond the schema, only implying entity indexing without explaining parameter interactions or constraints like when 'entity_two' is required. Baseline 3 is appropriate given high schema coverage.

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 ('Add a geometric constraint') and resource ('in the active sketch'), with specific mention of how entities are referenced ('by index within the sketch'). It distinguishes from siblings like 'create_sketch' or 'draw_line' by focusing on constraints rather than creation or drawing, though it doesn't explicitly differentiate from all constraint-related tools (none listed).

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, prerequisites (e.g., needing an active sketch), or exclusions. It mentions the active sketch but doesn't clarify if other tools might be needed first or when constraints are applicable in a workflow.

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