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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavior: a per-call price of $0.001 USDC, the x402/Solana payment requirement, and an alternative HTTPS endpoint. It also gives the recurrence and sample values (a(4)=2, a(6)=13) so a caller can sanity-check results, though it never states the return type.

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?

Five short sentences, purpose front-loaded, no filler. The pricing/endpoint sentences are operationally necessary; the two worked examples are slightly optional but earn their place as verification anchors.

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 and a single integer parameter, the description supplies the definition, domain, cost, and access route, which is nearly everything needed. The remaining gap is that it never states the return type/value explicitly or distinguishes itself from recaman_seen.

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 parameter meaning; it does clarify that n is the term index and that it runs 0 to 100000 (matching the schema bounds), and the recurrence explains what n indexes into. It adds no format or edge-case detail beyond that, so it partially compensates for the empty 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?

States a specific resource and operation: 'The nth Recamán term', immediately telling the agent this computes a Recamán sequence value at index n. However, it never mentions the sibling tool recaman_seen, so an agent cannot tell from the description alone which of the two Recamán tools to pick.

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?

No when-to-use or when-not-to-use guidance is given, and the obvious alternative (recaman_seen) is not referenced. The only constraint offered is the domain of n (0 to 100000), which is a limit rather than selection guidance.

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