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

Adds real context beyond the annotations: every returned name is grounded against live availability and Atom premium inventory, ungrounded ideas are filtered out, and the status/price fields are explained. Since readOnlyHint/destructiveHint already cover the safety profile, this is strong, though it omits cost/latency implications of live lookups and any server-side cap behavior on 'count'.

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?

Front-loaded with purpose, then routing, then return shape — a sensible ordering with no filler sentences. The return-format paragraph is somewhat long given an output schema exists, but it carries presentation guidance rather than restating the schema.

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?

An output schema exists, yet the description still supplies the wiring an agent needs: how to treat 'available' vs 'premium' and how to present results. Minor gap: nothing about how extensions or count caps affect outcomes, but the schema covers those adequately.

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 all five parameters (concept, count, style, industry, extensions) are already documented in the schema. The description adds no field-level meaning beyond implying that 'style' surfaces as style_tags in the results, so the baseline 3 applies.

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?

Opens with a specific verb and resource ('Invent NEW brandable domain name candidates') and immediately states the grounding step that makes the output distinctive. It explicitly positions itself against the sibling 'search_brandable_domains', so an agent can pick between them without reading either schema.

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?

Names both trigger conditions (curated results insufficient, user wants fresh/invented/registerable names) and names the alternative with a preference rule ('For existing curated listings, prefer search_brandable_domains'). This is explicit when-to-use and when-not-to-use guidance.

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