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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false. Beyond that, the description usefully discloses the $0.001 USDC per successful call x402 payment model on Solana and an HTTPS endpoint, which are important operational details not captured by annotations.

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 description is short and front-loaded with the core definition, followed by examples, domain, pricing, and endpoint. Every sentence adds practical value, and there is no redundant or filler prose.

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?

This is a simple one-parameter predicate with full annotation coverage and no output schema. The description defines the property, gives true/false examples, states the input domain, and includes cost and alternate endpoint details, leaving no significant ambiguity for 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 description coverage is 0%, so the description must carry semantic meaning for the sole parameter n. It explains that n is the number whose proper divisors are considered and restates the 1-to-20000 domain, which compensates for the missing parameter description even though the range is also present in the schema.

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 mathematical predicate: whether some subset of the proper divisors of n sums to n, with examples that clarify the concept. It is clear what the tool computes, but it does not explicitly differentiate itself from nearby sibling concepts such as perfect_check or practical.

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 description gives the valid domain of n and pricing, but it does not say when to use this tool versus alternatives like perfect_check, weird, or practical. There are no explicit when-to-use or when-not-to-use guidelines, so the agent must infer applicability from the tool name and definition.

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