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

No annotations are provided, so the description carries the full behavioral burden. It discloses return fields (amount, interest, effectiveAnnualRate) and a free-trial limit per signed wallet, but omits auth requirements after trial, error behavior, parameter defaults, and units—leaving key operational details unstated.

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 definition is one tight sentence plus a trial note, front-loading the core purpose and return values. It is appropriately sized, though the emoji and trial note add slight noise without harming readability.

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 9-parameter tool with 0% schema description coverage, no annotations, and no output schema, the description is too thin. It omits parameter formats, required fields, compounding options, units, and post-trial behavior—all needed for 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?

Schema coverage is 0% for 9 parameters. The description names principal, rate, time, and compounding, which partially maps to four concepts, but it never links these to the schema keys (p, r, n, years, etc.), specifies units, required/optional status, or alias relationships. This is not enough to compensate for the undocumented schema.

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 specific verb ('Computes') and resource ('compound interest'), and lists inputs and outputs. It does not explicitly distinguish itself from sibling tools like x402-compound or x402-simple-interest, so it misses the sibling-differentiation that would earn a 5.

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?

Provides no when-to-use or when-not-to-use guidance and names no alternatives. The only selection-relevant note is the free-trial limit, which does not help an agent choose this tool over x402-simple-interest or x402-compound.

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