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

With no annotations, the description carries the full burden but does disclose two useful traits: the result is rounded to cents, and there is a metered '5 free trial calls per signed wallet' access model. It does not state input units/format expectations (string vs number) or error behavior.

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?

One front-loaded sentence covering purpose and inputs, plus a short billing note. Minimal waste, though the emoji trial line is slightly extraneous to the tool's function.

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 pure-computation tool with no output schema and no annotations, the description covers what it computes and its inputs but omits the input value convention and the shape of the returned price, leaving the agent to guess.

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% and the four params are untyped strings, so the description must compensate. It does give each parameter meaning and semantic units ('coupon percent', 'rate percent', 'years'), but leaves the string encoding (e.g. '5' vs '0.05', decimals) unspecified.

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+resource ('Computes bond price') and enumerates the exact inputs, so an agent can distinguish it from siblings like x402-bond-yield, x402-bond-duration and x402-bond-convexity by the inputs/output involved.

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?

No when-to-use guidance, no mention of prerequisites or when to prefer a sibling such as bond-yield. The agent must infer the use case from the tool name alone.

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