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

The annotations already declare readOnlyHint, idempotentHint, non-destructive behavior. The description adds useful behavioral context beyond that: per-success pricing, x402/Solana payment details, and an alternate HTTPS endpoint. It does not explicitly describe the return value, though 'How many' strongly implies an integer count.

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-loads the core count definition before adding range, pricing, and endpoint details. The example sentence is slightly cryptic and could be phrased more clearly, but it does not waste much space.

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 one-parameter count tool with safety annotations, the description supplies the input range, examples, cost, and alternate access path. It could explicitly state the integer return type or define 'highly composite', but the essentials for correct invocation are 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 explain the single parameter. It clarifies that n is an inclusive upper bound ('from 1 through n'), repeats the 1–20000 range, and gives example counts for n=10, 60, and 120, though the 'There are 4 through 10' wording is terse.

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 clearly states that the tool counts highly composite numbers from 1 through n, which is a specific verb and resource. It does not explicitly contrast with siblings such as highly_composite or highly_composite_next, so it stops short of full sibling differentiation.

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 count-oriented phrasing and the n range, but there is no explicit guidance on when to use this versus highly_composite or highly_composite_next. It provides examples but no when/when-not rules or alternatives.

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