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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely non-obvious operational facts: a per-call price of $0.001 USDC via x402 on Solana and an equivalent HTTPS endpoint. It stops short of saying what happens on payment failure or whether results are cached.

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 core definition, then examples, then domain, then payment/transport logistics. The pricing and URL sentences are not needed to invoke the tool correctly, but they are short and clearly separated from the functional content.

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 no annotations explaining returns, the description still makes the return value obvious (a count of Moser-de Bruijn numbers ≤ n) and validates it via five concrete input/output examples. Nothing material is missing for correct invocation, though error/edge behavior at n=1000000 is unstated.

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?

The single parameter has 0% schema description coverage, so the description carries the burden and does: it defines n as the inclusive upper threshold ('at most n'), states the valid domain 0–1000000, and clarifies that 0 itself is counted. The bounds merely restate the schema, but the inclusive semantics and 0-handling are real value-add.

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 precise verb+resource: the counting function of Moser-de Bruijn numbers up to n, with worked examples (through 5 there are 4) that pin down the inclusive, 0-counting semantics. That implicitly separates it from siblings like moser_sum or moser_index, but it never names those siblings explicitly.

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: an agent can infer this is the counting variant, but there is no explicit statement of when to pick moser_count over moser, moser_check, moser_index, or moser_sum, nor any prerequisites or exclusions.

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