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

Annotations already cover safety (readOnly, idempotent, openWorld, non-destructive), and the description adds important extra context: the $0.001 USDC cost per successful call via x402 on Solana and an HTTPS alternative endpoint. It does not explicitly state the boolean return shape, but 'Whether' strongly implies it.

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 description is front-loaded with the core predicate, then adds a clarifying example, constraints, pricing, and an alternative endpoint. Each sentence earns its place, though the worked example is slightly more illustrative than strictly necessary.

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 simple two-parameter predicate with no output schema, the description provides enough to call it correctly: it states the predicate, the even constraint on n, parameter ranges, cost, and an alternate transport. A minor gap is that it does not explicitly say it returns true/false.

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 0% schema description coverage, the description compensates by explaining that n is even, giving n’s range 4–10000, p’s range 2–10000, and clarifying the relationship that both p and n-p must be prime. The even constraint for n is not in the schema and is valuable; the p range merely repeats schema bounds.

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 states a specific predicate: whether p and n-p are both prime. That is clear enough to understand the operation, but it does not explicitly differentiate from siblings like goldbach or goldbach_count, so an agent must infer that this is the single-pair check.

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?

There is no guidance on when to use this tool versus alternatives such as goldbach or goldbach_count. The examples illustrate valid calls but do not explain selection criteria or exclusions.

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