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

Annotations already establish that the tool is read-only, idempotent, and non-destructive. The description adds important operational behavior beyond annotations: pricing per successful call, payment via x402 on Solana, and an equivalent HTTPS POST endpoint. It stops short of describing error behavior or rate limits, but it is substantially more informative than the annotation layer alone.

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 front-loaded with the core mathematical definition, then adds a compact formula, a concrete example, the input range, and invocation/payment details. Every sentence contributes useful information and there is no apparent filler.

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 mathematical tool with no output schema, the description supplies the computed return meaning, the closed-form property, an example, the input bounds, and payment/endpoint context. An agent has enough information to call it correctly without additional structured documentation.

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 the burden for the single parameter n. It clarifies that n is the inclusive upper bound of the range 1..n and states the valid range 1 to 1000000000000, which adds semantic meaning beyond the raw integer type and constraints.

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 a specific computation: the largest ruler value on 1..n and the smallest index where it occurs. It distinguishes the tool semantically from siblings like ruler_sum or ruler_prefix by emphasizing the maximum and its index, but it does not explicitly name or compare against 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?

The description explains what the tool computes and the valid range for n, but gives no explicit guidance on when to choose this tool over ruler, ruler_odd, ruler_prefix, or ruler_sum. Operational details such as pricing and the HTTPS endpoint are present, but they do not substitute for usage routing among alternatives.

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