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

Annotations only declare readOnlyHint and openWorldHint, so the description carries real weight here and delivers: results are checked live, capped at 15 names, each marked taken/likely available, TLDs customizable, and critically it discloses a $0.005 USDC per-call charge via x402 — a cost signal an agent must know before invoking.

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?

One dense sentence that front-loads the value proposition, then the TLD scope, then the price. Every clause carries information; it is slightly long but no clause is filler.

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 two-param, no-output-schema tool with thin annotations, the description covers output shape (15 availability-marked names), TLD configurability, and the payment model. The main remaining gap is payment mechanics (wallet/credential prerequisites for x402) and the tlds input format.

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 description coverage is 0% with two params, so the description must compensate. It maps 'idea' (business idea) and 'tlds' (or your TLDs), but gives no format guidance for the tlds string (comma-separated? dot-prefixed? count limits), leaving invocation detail to guesswork.

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?

Specific verb+resource ('Brandable domain ideas') with a clear scope: up to 15 short names across named TLDs, availability-checked. Distinguishable from sibling domain tools (domain, domain_audit, report_domain) which do lookups/audits rather than ideation.

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?

The description implies the use case (you have a business idea and want name candidates) and states the output intent, but never states when to prefer this over sibling tools like domain, domain_audit or report_domain, nor any prerequisites beyond the idea input.

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