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

No annotations are provided, so the description carries the burden. It states the calculation behavior but does not disclose return format, side effects, or any safety context. Since it's a simple calculator, the information is minimal but not misleading.

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 sentences, front-loaded with the tool's name and purpose, and wastes no words. The second sentence concisely explains inputs and expected outcome.

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?

With no output schema, the description could be more explicit about what results the user receives. It implies profitability analysis but does not specify the output format or formulas. For a simple calculator, this is adequate but leaves room for improvement.

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%, and the description names all three parameters (revenue, ad spend, gross margin) but does not add units, formulas, or interpretation. It gives basic meaning beyond the schema names, but not deeply.

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 calculates ROAS and break-even ROAS, with specific mention of inputs and the profitability purpose. It distinguishes from generic ROI calculators by focusing on ROAS and campaign profitability.

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 the tool: to evaluate if a campaign is truly profitable using revenue, ad spend, and gross margin. It does not explicitly mention alternatives or exclusions, but the use case is well implied.

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