plot_pie

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'Render circular pie chart' but doesn't explain what rendering entails (e.g., generates an image file, displays in UI, returns data), any performance considerations, or error handling. The example shows input structure but lacks behavioral context, leaving significant 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 front-loaded with the core purpose and includes a concise example. The sentences are efficient, with no wasted words. However, the example could be more integrated into the text rather than standalone, and some redundancy exists (e.g., 'Simple flat parameters' is implied by the schema).

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 (rendering a chart with multiple parameters), no annotations, and an output schema (which reduces the need to describe return values), the description is partially complete. It covers basic input structure but lacks behavioral details, usage context, and full parameter explanations, making it adequate but with clear gaps.

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 compensate. It provides an example with labels, values, and title, which adds meaning for those parameters. However, it doesn't cover all parameters (e.g., width, height, inner_radius_ratio, start_angle) or explain their semantics (e.g., units, constraints). This partial coverage meets the baseline but doesn't fully address the schema gap.

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 tool's purpose: 'Render circular pie chart.' It specifies the resource (pie chart) and verb (render), making it easy to understand what the tool does. However, it doesn't explicitly differentiate from sibling tools like plot_bar or plot_scatter beyond the chart type, which prevents a perfect score.

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. With sibling tools like plot_bar and plot_line available, there's no mention of scenarios where a pie chart is appropriate (e.g., for showing proportions) or when other chart types might be better. This lack of context leaves the agent without usage direction.

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