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

Goes well beyond the readOnly/idempotent annotations by disclosing the paid access model ($0.001 USDC per successful call via x402 on Solana) and an equivalent HTTPS POST endpoint. Pricing and payment-path details are exactly the kind of operational context an agent cannot get from structured fields.

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?

Front-loaded with the definition, then examples, then the domain constraint, then commercial/transport details. Every clause is relevant, though five example mappings is slightly more than needed to convey the function.

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?

With no output schema, the description still conveys the return value (an integer sum) through the worked examples, and it covers input bounds, cost, and an alternative transport. It omits what happens when n is out of range, which is the only meaningful remaining gap for a single-parameter pure function.

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 coverage is 0%, so the description must carry the load, and it does: the valid domain 1..1000000 is restated and five worked n→result pairs demonstrate what the single parameter means in practice. It stops short of explicitly defining n as the integer whose exponential divisor sum is taken, but the examples make it unambiguous.

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?

States a specific verb and resource: 'sum of the exponential divisors of n'. That implicitly separates it from siblings like exp_divisors (list) and exp_count, though it never names those alternatives. An agent can tell what it computes, but must infer the sibling split.

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 only implied by the mathematical purpose and the stated domain 'n runs from 1 to 1000000'. There is no explicit when-to-use, no exclusion, and no pointer to exp_divisors / exp_count / exp_next for adjacent needs, despite those siblings existing.

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