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

No annotations are provided, so the description carries the full burden. It does disclose the computation and that the result is expressed as a percentage, plus a pricing note about 5 free trial calls per signed wallet, which is useful context. It does not address edge behavior such as a zero or missing value, whether inputs accept decimals or formatted strings, or what an error response looks like.

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?

Two short sentences, front-loaded with the tool name and the defining formula, then the required inputs. Minimal waste; only the parenthetical '(cap rate)' is mild redundancy with the tool name.

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 deterministic two-input calculator with no output schema and no annotations, the description supplies the formula, the unit of the result, and the required inputs — enough to call it correctly. Remaining gaps (input format, error behavior) are small given the tool's simplicity.

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% and the schema only declares two untyped strings, so the description must compensate. It does define the meaning of both parameters — noi as net operating income and value as property value — and links them through the formula, which is meaningful added semantics. It stops short of clarifying that the declared type is string and what numeric format is accepted.

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 and resource ('Calculate the capitalization rate') and backs it with the exact formula (NOI divided by property value) plus the output unit (percentage). An agent knows precisely what this produces without consulting any sibling tool.

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 sentence 'Provide noi and value' tells the agent what inputs to supply, which implies when the tool is applicable, but there is no explicit statement of when to prefer it over alternatives (e.g. related finance tools such as x402-roi-calc or x402-enterprise-value) and no preconditions or exclusions.

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