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

No annotations exist, so the description carries the full burden. It usefully discloses the computation itself and a payment/auth condition ('5 free trial calls per signed wallet'), but says nothing about input format, units, or edge cases such as a zero interest expense.

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?

Front-loaded single sentence that leads with the metric name and formula, with no wasted words. The trailing trial/emoji promo is minor noise but conveys payment context.

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?

For a simple two-input calculator with no annotations and no output schema, the description covers the formula but not input encoding, rounding, or zero-denominator behavior. Adequate as a minimum viable definition, incomplete for an agent that needs to format inputs correctly.

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%, so the description must compensate. It does explain the relationship of both params to the output (EBIT and interest expense), but gives no format or type guidance (both are strings, presumably decimal numbers) and no unit conventions.

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?

States a precise verb (computes), a specific named metric (interest coverage ratio), and the exact formula (EBIT / interest expense). That formula cleanly separates it from neighbouring ratio tools like x402-debt-service-coverage or x402-current-ratio without needing to name them.

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 when-to-use guidance, no prerequisites, and no mention of alternatives or when-not to use it. The agent must infer from the name alone that this is a financial health/dividend-safety ratio rather than a generic calculator.

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