generate_scatter_chart

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

Annotations indicate readOnlyHint=true, suggesting this is a safe read operation (likely generating a chart without side effects). The description doesn't contradict this, as 'Generate' aligns with a read operation in this context. However, it adds minimal behavioral context beyond annotations—it mentions the chart's purpose but not details like output format (e.g., image URL, base64), performance considerations, or error handling. With annotations covering safety, a 3 is appropriate for limited added value.

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, efficient sentence that front-loads the core purpose. It avoids redundancy and wastes no words. However, it could be slightly more structured by separating usage context from purpose, but it's still highly concise and clear.

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 complexity (8 parameters, nested objects) and lack of output schema, the description is minimally adequate. It states what the tool does but doesn't cover output details (e.g., what is returned—a chart image, data, or error), performance limits, or advanced usage scenarios. With annotations providing safety info and schema covering parameters, it meets a basic threshold but leaves gaps for agent invocation.

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%, meaning all parameters are documented in the schema. The description adds no specific parameter information beyond the general purpose of showing relationships between variables. It doesn't explain parameter interactions, defaults, or usage examples. Given the high schema coverage, the baseline is 3, as the description doesn't compensate but also doesn't detract.

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: 'Generate a scatter chart to show the relationship between two variables.' It specifies the verb ('Generate') and resource ('scatter chart'), and mentions the goal of discovering relationships or trends. However, it doesn't explicitly differentiate this from sibling tools like 'generate_line_chart' or 'generate_bar_chart' beyond the scatter chart type, which keeps it from 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. It mentions that scatter charts help discover relationships or trends, but doesn't specify scenarios where a scatter chart is preferred over other chart types (e.g., line charts for time series, bar charts for categorical comparisons). There's no mention of prerequisites, exclusions, or explicit alternatives among the sibling tools.

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