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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and non-destructive behavior, so safety is covered. The description adds useful behavioral context beyond annotations: paid x402 access on Solana, the exact price per successful call, and an equivalent HTTPS endpoint. It does not explain payment flow or failure behavior, which keeps it from a 5.

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 definition is front-loaded, followed by concise examples, the valid range, and payment/endpoint details. Every sentence contributes relevant information without unnecessary verbosity.

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 read-only tool with one parameter and no output schema, the description provides enough context: output meaning, input range, examples, cost, and endpoint. It could be slightly more complete by defining 'self number' formally or describing the response payload, but the essential invocation context is present.

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 compensate, and it does by stating that n runs from 1 to 100000 and giving concrete input-output examples. The examples add meaning beyond the schema's bare integer bounds, though the general definition of a self number is not formally supplied.

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 result: the smallest self number that is at least n, and gives examples that clarify the mapping. It is distinguishable from siblings such as self_nth or self_count by its 'next at least n' behavior, though it does not explicitly name those alternatives.

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?

Usage is implied by the definition and examples, and the valid input range is stated. However, there is no explicit when-to-use guidance, no when-not conditions, and no naming of sibling alternatives such as self_number or self_nth.

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