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. It offers only the mathematical definition and says nothing about how the tool receives the number it operates on, what the return value looks like, or how edge cases (n=0, n=1, negative numbers) behave. The 'proper divisors' clarification adds some value, but essentially all behavioral context beyond the definition is missing.

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?

A single eight-word sentence that front-loads the operation name followed immediately by the precise definition. Every word earns its place; there is zero fluff and the size is appropriate for a trivial mathematical utility. This is exemplary conciseness, not under-specification.

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 tool with no annotations, no output schema, and — most critically — an empty input schema despite being a per-number computation, the description is incomplete. It never addresses how the input number is supplied or what the caller should expect in return. The tool's complexity is low, but the gap between the described operation and the declared interface is large and unexplained.

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?

The input schema is empty (0 parameters), so the baseline of 4 applies — there are no parameter fields for the description to document. The description does add conceptual meaning by defining what the tool computes. However, it conspicuously fails to explain how a per-number computation receives its input when the schema declares none, which an agent will have to discover elsewhere.

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 states a specific computation — 'Sum of proper divisors' — which tells an agent exactly what the tool does and clarifies the mathematical meaning of 'aliquot sum' (proper divisors exclude the number itself). It doesn't explicitly contrast with siblings like x402-aliquot-sequence or x402-amicable-pair, but the operation and resource are clear enough that an agent can infer the function. Minor deduction because the opening phrase 'Aliquot Sum:' largely restates the tool name.

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 guidance whatsoever on when to invoke this tool versus any of the many related number-theory siblings (x402-aliquot-sequence, x402-amicable-pair, x402-perfect-numbers, x402-is-abundant, etc.). No conditions, prerequisites, exclusions, or alternative routing are mentioned. The absence of guidance is especially acute given the tool's empty parameter schema, which would leave an agent unsure how to use it at all.

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