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, and it discloses nothing: not the formula, not whether inputs are values or dates, not required permissions, not how partial inputs are handled. A calculation tool with zero annotation coverage should at minimum describe its computation model, and this does not.

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 text is short but wastes its single sentence on a tautology rather than front-loading anything useful. This is under-specification rather than genuine conciseness, so the brevity earns no credit.

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?

With three parameters, no annotations, and no output schema, the description would need to explain the input model and result shape, and it does neither. It is not complete enough for an agent to invoke the tool with confidence.

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 nominally 100%, but the parameter descriptions are boilerplate placeholders ('End to process', 'Start to process', 'Years to process') that convey nothing about whether start/end are monetary values, dates, or something else. The description adds no parameter meaning at all, leaving a genuinely ambiguous interface for an annualized-return 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 'Annualized Return: Annualized return calculation' merely restates the tool name with no added specificity — no indicator of what inputs it consumes, what formula it uses, or what kind of return it computes. It does not distinguish itself from close siblings such as x402-cagr, x402-returns, x402-roi, or x402-holding-period-return.

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 exclusions, and no mention of any alternative. An agent cannot tell from this text why it would pick this over x402-cagr or x402-returns, which sit adjacent in the same family.

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