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

No annotations exist, so the description carries the burden. It usefully discloses the exact computation and output precision ('rounded to two decimals'), implying a safe, deterministic read-only calculation. It omits any statement of response shape, input validation behavior, or error handling for malformed inputs.

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 with the formula, plus a short trial-credit note. Minimal waste, though the emoji and pricing clause are peripheral 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 two-parameter calculator with no annotations and no output schema, the description supplies the formula and rounding but leaves the return value shape, input format, and edge-case behavior undefined. Adequate but with clear gaps.

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%, so the description must compensate. It effectively defines both parameters through the formula: 'dividend' is dividend per share and 'price' is the divisor. It does not specify accepted input format (schema declares strings) or that both are required/optional, which keeps it from a 5.

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 ('Dividend Yield') and gives the exact formula (dividend per share / price × 100), which is more than the name alone conveys. It does not name or differentiate from close siblings like x402-current-yield, x402-dividend-payout-ratio, or x402-earnings-yield, so it falls short of 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?

The only guidance offered is a pricing note ('5 free trial calls per signed wallet'). There is no statement of when to use this tool versus related yield calculations, no prerequisites, and no exclusions.

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