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

Annotations cover readOnly/idempotent/non-destructive/openWorld, so the safety profile is known. The description adds materially useful behavior: per-call cost of $0.001 USDC via x402 on Solana and an alternate HTTPS endpoint. These payment and access details are not in any structured field and are important for correct invocation. No contradiction with annotations.

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, then pricing and endpoint. Every sentence carries distinct information with no filler; the pricing line is required for x402 tools and is placed last where it doesn't obscure usage.

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 one-parameter read-only tool with no output schema, it supplies the definition, bounds, worked return-value examples, cost, and an alternate endpoint. The main remaining gap is that it never defines what the Moser-de Bruijn numbers actually are, which would help an agent reason about correctness of output.

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?

With a single parameter, the baseline is high. Schema coverage is 0%, but the description nearly compensates: it clarifies n is the inclusive upper bound ('a(0) through a(n)'), restates the 0-5000 range, and provides output examples at n=0,3,5,7. It does not define the Moser-de Bruijn sequence itself, which an agent might not know, so not a full 5.

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: the cumulative sum of Moser-de Bruijn numbers a(0) through a(n). This clearly distinguishes it from siblings like moser (likely single term) or moser_count, though it doesn't explicitly name those alternatives. Worked examples (through 0 is 0, through 3 is 10) confirm exactly what is computed.

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 guidance on when to use this versus the sibling moser, moser_check, moser_count, moser_index, or the dozens of other *_sum tools. The domain bound (n 0-5000) and examples are present, but the agent is left to infer that this is the cumulative-sum variant.

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