roi_calc

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

With no annotations, the description carries the full burden of behavioral disclosure. It does usefully mention that the tool costs $0.001 USDC via x402, but it provides no information about what the tool actually does, what scenarios it supports, what side effects exist, or what kind of output to expect.

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 very short, but it is under-specified rather than appropriately concise. The first sentence is a tautology and the second sentence only covers cost, so neither sentence fully earns its place by conveying tool-specific meaning.

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?

ROI calculation is a nontrivial domain with multiple possible inputs (e.g., initial investment, returns, time period) and formula variants. With no output schema, no annotations, and a generic params schema, the description is far too sparse to enable correct 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?

The input schema only defines a generic 'params' object with no domain-specific fields. The description adds absolutely no parameter semantics, so an agent has no idea what keys or values to include for an ROI calculation.

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 'roi calc — Finance & Math tool' is essentially a restatement of the tool name with a generic category label. It does not explicitly say that the tool calculates return on investment or any other specific function, and it does not distinguish this tool from the many other finance calculators in the sibling list.

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?

There is no guidance about when to use this tool versus any alternative. The only additional context is the cost/payment method, which does not help an agent decide between roi_calc and related calculators like loan_calculator, cagr_calc, or simple_interest_calc.

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