generate_waterfall_chart

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

Annotations indicate readOnlyHint=true, which the description does not contradict (it describes a generation/visualization tool, not a destructive operation). The description adds useful context about what the tool produces (a visualization of cumulative effects) and typical use cases, but does not disclose additional behavioral traits like rate limits, authentication needs, or output format details. With annotations covering the safety profile, this is adequate but not rich in 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 appropriately sized and front-loaded: it starts with the core purpose, then explains the visualization concept, and ends with ideal use cases. Both sentences earn their place by adding value. It could be slightly more concise by combining some phrases, but it avoids redundancy and waste.

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 (8 parameters, nested objects) and rich schema coverage (100%), the description provides good contextual completeness. It explains the tool's purpose, use cases, and what it visualizes. Since there is no output schema, it does not describe return values (e.g., chart format or output type), which is a minor gap. However, for a generation tool with detailed schema, the description is largely 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?

Schema description coverage is 100%, so the schema already documents all 8 parameters thoroughly with descriptions and examples. The description does not add any parameter-specific information beyond what the schema provides. According to the rules, when schema coverage is high (>80%), the baseline score is 3 even with no param info in the description, which applies here.

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 waterfall chart to visualize the cumulative effect of sequentially introduced positive or negative values.' It specifies the verb ('generate') and resource ('waterfall chart'), distinguishes it from siblings by explaining what waterfall charts are ideal for (financial analysis, budget tracking, etc.), and provides concrete examples of use cases that differentiate it from other chart types.

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 clear context for when to use this tool: 'Waterfall charts are ideal for financial analysis, budget tracking, profit and loss statements, and understanding the composition of changes over time or categories.' This gives the agent guidance on appropriate scenarios. However, it does not explicitly state when not to use it or name specific alternatives among the many sibling chart tools, which prevents a score of 5.

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