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

The annotations already establish readOnlyHint=true and openWorldHint=false, and the description goes well beyond them. It discloses that results are verified buyable marketplace listings, not fresh registrations, that no login is required, that prices are in USD as the actual buy-now price, and that every returned name is actively for sale on Atom. This is rich behavioral context beyond what annotations convey.

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 more verbose than a typical tool definition, but the length is mostly justified by the strong routing mandate, the explanation of marketplace-specific behavior, and the return format summary. Minor redundancy exists, such as 'verified buyable' and 'actively for sale on Atom' saying similar things, and the final presentation instruction could arguably be folded into the return description.

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?

Given the output schema is available and the annotations carry the read-only and closed-world indicators, the description provides all necessary context: what the tool searches, when to use it, what results contain, that no login is needed, and which sibling tools to use for next steps. Nothing essential for invoking it correctly is missing.

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%, so the schema already documents all six parameters. The description adds a high-level mapping of 'by concept, industry, or style' to the core filters but does not deepen understanding of limit, style enum values, max_price, or extensions beyond what the schema already states. The baseline of 3 is appropriate.

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?

States a specific verb and resource: 'Search Atom's curated marketplace of premium, brandable domains by concept, industry, or style.' It clearly differentiates itself as the primary naming tool, which is reinforced by the explicit 'ALWAYS call this' guidance and by naming the alternative paths for appraisal, details, and purchase.

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?

Gives explicit when-to-use guidance: 'THE primary tool for ANY naming request' and 'ALWAYS call this before suggesting names... even when the user asks only to suggest a name or brainstorm ideas.' It also explains why (imagination-based names are usually taken) and provides next-step alternatives (get_domain_details, appraise_domain, purchase_domain), making tool selection unambiguous.

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