art.canvas.draw_rect

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

There are no annotations, so the description bears the full burden of explaining behavior. It only states the basic action and does not disclose coordinate system assumptions, whether the drawing overwrites existing content, how the filled parameter behaves, or any side effects. This is minimal 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 a single declarative sentence with no redundant words. It is immediately front-loaded with the core action and resource, making it very easy to scan and understand.

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 7 parameters, 6 required, and no output schema, the description is too thin. It omits context that would help an agent use it correctly, such as coordinate system, integer bounds, canvas requirements, fill defaults, or interactions with the existing canvas state.

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 100%, so the schema already explains all seven parameters including x, y, width, height, color, filled, and session_id. The description adds no parametric meaning beyond the schema, so the baseline 3 is appropriate.

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 states a specific action (draw) and a specific resource (a rectangle), clearly identifying the tool's function. It naturally distinguishes itself from sibling canvas tools like draw_line and draw_circle by naming the shape being drawn.

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 such as draw_circle, fill, or batch_draw. It does not mention any preconditions, context, or exclusions, leaving the decision entirely to the agent.

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