art.canvas.draw_circle

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

No annotations are provided, so the description carries the full responsibility for behavioral disclosure. It does not mention whether the circle overwrites existing content, whether the filled parameter affects the result, what coordinate system is used, or what side effects the operation has. The one-sentence description is minimal and does not provide enough 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 very short, focused, and front-loaded with the primary action. All words are relevant, though the minimal nature sacrifices useful context in other dimensions. It is concise without being bloated.

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 simple drawing primitive, the description plus the fully-described schema might be minimally viable. However, there are gaps around canvas session requirements, coordinate bounds, how filled interacts with the visual result, and what other canvas tools should be used in combination. The lack of any output schema makes the description less a problem about returns, but these situational gaps remain.

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?

The schema already provides 100% description coverage for parameters like cx, cy, radius, color, filled, and session_id. The description adds no additional parameter-level meaning, but since the schema is fully self-contained, the baseline of 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 clearly states what the tool does: 'Draw a circle on the canvas.' It names a specific verb, resource, and the primitive being created, which differentiates it from sibling canvas tools such as draw_rect and draw_line. The behavior is unambiguous even with minimal text.

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?

There is no guidance about when to use this tool versus alternatives like draw_line or draw_rect, nor are there prerequisites explained, such as having a valid canvas session. The description only states the action and leaves all usage context to be inferred from the schema.

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