fusion_sketch_add_rectangle

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

Without annotations, the description must carry behavioral transparency. It implies a mutating operation (adding to a sketch) but doesn't disclose whether it modifies existing geometry, what happens if the sketch doesn't exist, or if the rectangle is axis-aligned. The mention of units (mm) adds some context, but otherwise the behavior is underspecified.

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 sentence with no wasted words, which is appropriate for conciseness. It front-loads the core action and parameters. However, the extreme brevity borders on under-specification rather than effective conciseness, so a score of 4 reflects efficiency without penalizing should-be-longer content.

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 and no output schema or annotations, the description is incomplete. It doesn't explain how coordinates are interpreted (absolute/relative), whether the rectangle is centered or corner-based, or what the return value is. The description only covers the basic action, leaving the agent to guess on critical details.

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 0%, so the description must explain the parameters. It mentions 'two opposite corners (mm)', which maps to x1,y1 and x2,y2, but does not clarify what 'sketch_id' is or provide example values. The description adds minimal meaning beyond the bare property names in the schema.

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 operation: 'Add a rectangle to a sketch' using two opposite corners. It distinguishes itself from sibling sketch tools (line, circle) by specifying the rectangle shape and corner-based definition. However, it doesn't explicitly mention the coordinate system or orientation, so it's clear but not fully specific.

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 fusion_sketch_add_line or fusion_sketch_add_circle. There is no mention of prerequisites (e.g., an active sketch) or scenarios where this tool is preferred. The description only states the what, not the when.

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