generate_sankey_chart

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

Annotations provide readOnlyHint=true, indicating this is a safe read operation (likely generating a chart without side effects). The description doesn't contradict this, but adds minimal behavioral context beyond annotations—it mentions the visualization purpose but doesn't disclose output format (e.g., image file, URL), performance considerations, or any limitations. With annotations covering safety, the description adds some value but not rich behavioral details.

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 with a helpful example. It avoids redundancy and wastes no words, making it appropriately sized for a chart-generation tool. However, it could be slightly more structured (e.g., by explicitly noting key parameters) to enhance clarity.

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 complexity (7 parameters with nested objects) and lack of output schema, the description is minimally adequate. It states the purpose and provides an example, but doesn't explain the return value (e.g., chart image or data), error conditions, or advanced usage. With annotations covering safety and schema covering parameters, it meets basic needs but leaves gaps for full agent understanding.

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 fully documents all 7 parameters with descriptions and defaults. The description adds no parameter-specific information beyond what's in the schema (e.g., it doesn't explain 'data' structure or 'style' options further). Baseline is 3 when schema does the heavy lifting, and the description doesn't compensate with additional semantics.

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 sankey chart to visualize the flow of data between different stages or categories.' It specifies the verb ('generate') and resource ('sankey chart') with a concrete example (user journey). However, it doesn't explicitly differentiate from sibling tools like 'generate_flow_diagram' or 'generate_funnel_chart' that might also visualize flows, missing full sibling distinction.

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 implied usage guidance through the example ('such as, the user journey from landing on a page to completing a purchase'), suggesting it's for flow visualization between stages or categories. However, it lacks explicit when-to-use vs. alternatives (e.g., compared to other chart types in the sibling list) or any exclusions, leaving the agent to infer context.

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