draw_box

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

There are no annotations, so the description must convey side effects. It adds useful details like coordinate meaning, character units, and label placement, but does not disclose whether the box is filled/outline, whether existing content is overwritten, or what the return value is.

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 two concise sentences, front-loaded with the primary purpose and immediately followed by parameter semantics. No wasted words.

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 5-param drawing tool with no output schema and no annotations, the description covers the main purpose and parameters, but it omits behavioral details such as error handling, whether a canvas must already exist, and the return value. It is adequate but not fully complete.

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 documents all 5 parameters (100% coverage), so the baseline is 3. The description adds value by clarifying that w/h are measured in character units and that the label is centered on the top border, which the schema descriptions lack.

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 the core function: '在画布上绘制一个矩形框' (draw a rectangular box on the canvas), using a specific verb and resource. This clearly distinguishes it from siblings like draw_line and draw_arrow.

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 implies the tool is for drawing rectangles but offers no explicit guidance on when to use it over draw_line/draw_arrow, and does not mention any exclusions or prerequisites.

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