calculate_roi

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

With no annotations, the description caries the burden. It states the tool returns ROI %, profit, and multiple, implying a read-only computation. It does not disclose any potential side effects or constraints, but for a calculator this is minimal.

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 three sentences, front-loaded with the core purpose, and contains no filler. Each sentence adds value, and the reference to list_bundles is a helpful extra.

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 simplicity of the tool (two inputs, output schema present), the description covers purpose, inputs, outputs, and use cases. It doesn't address edge cases but is sufficiently complete for most agents.

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 coverage is 100% with clear parameter descriptions. The description summarizes the inputs as 'investment cost' and 'return value,' adding no new semantic information beyond the schema, so baseline 3 is appropriate.

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 computes ROI as a percentage and lists use cases (investments, marketing spend, projects). It distinguishes from siblings by being specific to ROI, though it doesn't explicitly name alternatives beyond a pointer to a bundle.

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 says 'Use to evaluate investments, marketing spend, or projects,' providing when to use. However, it offers no explicit when-not-to-use guidance or direct sibling names, just a reference to a bundle of related calculators.

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