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

Annotations already declare this as a read-only, idempotent, non-destructive operation, so the description mainly needs to add useful context. It does so by stating the domain range, pricing, payment mechanism (x402, Solana), and the equivalent HTTPS endpoint, though it does not explicitly state 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?

The definition is front-loaded, followed by compact examples, range, pricing, and endpoint. Every sentence contributes useful information without excess verbosity.

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 one-parameter predicate with no output schema, the description provides the full mathematical definition, concrete examples, valid range, and payment/access details. An agent has enough information to invoke it correctly and interpret the expected boolean result.

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%, but there is only one parameter and the description defines its semantic role by explaining what it means for n to start a triplet. It also repeats the valid range and gives examples of accepted and rejected values, adding useful meaning beyond the bare integer 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?

The description states a specific mathematical predicate: whether n begins a prime triplet, with both allowed triplet forms spelled out. It is clearly distinct from count/closely related prime tools in practice, though it does not explicitly name a sibling to differentiate itself.

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 implied by the definition of the predicate, but there is no explicit guidance on when to use this versus alternatives such as prime_triplet_count or prime_check. No exclusions or prerequisites are given.

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