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 computation performed, argument roles, rounding, or output form. An agent has no basis to predict what calling it does.

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?

It is very short, but brevity here stems from under-specification rather than efficiency. The single duplicated phrase is not front-loaded with any actionable content.

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 arithmetic tool with no annotations and no output schema, the description provides nothing: no formula, no argument semantics, no result format. It is wholly inadequate 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 100%, but the schema's own descriptions ('Total to process', 'Value to process') are equally generic and do not disambiguate which argument is the base and which is the percentage. The tool description adds no information to clarify the roles, so the intended baseline of 3 is not met.

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 is 'Percent Of: Percent Of' — a verbatim restatement of the tool name with no verb, resource, or scope added. It does not distinguish itself from near-identical siblings such as x402-percent-of-value, x402-percentage-of, or x402-ratio-of.

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 indication of when to use this tool versus the many sibling percent/ratio/percentage tools. No preconditions, exclusions, or alternatives are mentioned.

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