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

No annotations are provided, so the description carries the full burden of behavioral disclosure and delivers nothing. It does not state the return type (boolean?), edge-case behavior (e.g., whether 0 and 1 are considered coprime), input domain, or error handling.

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 tiny, but it is redundant duplication of the title rather than concise, front-loaded information. This is under-specification rather than economy of wording.

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 no annotations, no output schema, unusable parameter descriptions, and no explanation of inputs or outputs, an agent cannot reliably invoke this tool. For a numeric predicate the description should at minimum state that it accepts two integers and returns a boolean and how degenerate inputs are treated.

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 meaningless placeholders ('A to process', 'B to process') and both are typed as strings, leaving it unclear that a and b are integers to be tested. The description adds no meaning beyond the schema, and the schema itself conveys no usable semantics.

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 a verbatim restatement of the tool name ('Is Coprime Pair: Is Coprime Pair'), which is a tautology rather than an explanation. It does hint at the domain (checking whether two values form a coprime pair), but gives no verb, scope, or distinction from the many similar predicate siblings such as x402-is-prime-pair or x402-is-twin-prime-pair.

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 prerequisites, and no mention of any alternative tool, despite hundreds of near-identical 'is-*' predicate siblings where disambiguation is critical. An agent has no basis to prefer this over adjacent number-theory checks.

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