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

Annotations already declare readOnly/idempotent/non-destructive, so the safety bar is lower; the description adds real behavioral context the annotations lack: a per-call cost of $0.001 USDC via x402 on Solana and an equivalent HTTPS endpoint. It does not describe the response shape (an integer place), which is the remaining gap.

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 core semantic definition is front-loaded and the worked example earns its space by disambiguating an unusual output convention. The opening fragment 'When a seat is eliminated.' is awkward and the pricing/URL sentence, while useful, is slightly tacked on.

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 pure compute tool with no output schema and 0% schema coverage, the description should explicitly say it returns the place for the requested seat and should differentiate from the four adjacent josephus_* tools. It accomplishes the semantic definition but leaves the return value and sibling routing to the agent's inference.

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 parameter burden. It does constrain n (1..10000) and seat (1..n), and the example implicitly reveals k as the count step ('every 2nd'). But k is never named or bounded (1..10000), and the mapping of descriptions to parameter names is left to inference.

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 defines the specific quantity computed (the elimination 'place' of a given seat) and pins it down with a concrete worked example: 5 people, every 2nd, seat 2 -> place 1, seat 3 -> place 5. That is far more than a restatement of the name, but it never states the operation in a single explicit verb+output sentence, and it never distinguishes itself from the many Josephus siblings (josephus, josephus_first, josephus_k2, josephus_order).

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 josephus, josephus_order, josephus_first or josephus_k2, which is the agent's central problem in this sibling cluster. The only constraints given (seat between 1 and n, n up to 10000) are input-domain rules, not usage guidance or alternatives.

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