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

Annotations already flag readOnly/openWorld/destructive, and the description still adds real behavioral context: no login required, every returned name is verified buyable and actively for sale, and imaginary names are usually taken. It also pre-empts a common confusion by clarifying these are Atom marketplace listings rather than fresh registrations.

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 capability and the 'always call first' directive are front-loaded, and the return-value and next-step guidance follows logically. It runs long, with some reinforcement (the buyable/for-sale point is made twice), but nearly every clause is actionable rather than 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?

With an output schema present, the description needn't enumerate return values, yet it usefully summarizes results[] fields and the presentation format. Annotations cover the safety profile and the schema covers all params, so the only remaining gap is silent treatment of pagination/capped limits and style-enum semantics, which is minor.

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 100% and all six parameters (limit, style, concept, industry, max_price, extensions) are documented inline, so the schema carries the semantic load. The description only mentions 'by concept, industry, or style' at a high level and adds no new filter syntax, enum meanings, or limit/pricing caveats beyond the 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 names a specific verb and resource ('search ... marketplace of premium, brandable domains') and scopes it to concept, industry, or style. It also explicitly positions itself against naming siblings by declaring itself 'THE primary tool for ANY naming request,' so an agent can pick it without opening other schemas.

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?

It gives a strong, explicit trigger ('ALWAYS call this before suggesting names ... even when the user asks only to suggest a name') and names follow-on tools (get_domain_details, appraise_domain, purchase_domain) with their roles. What it does not do is say when a sibling like brainstorm_names or generate_domain_names would be preferred instead, so the alternative-routing is incomplete at the same-task level.

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