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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so the safety profile is covered. The description adds genuine value beyond that: it notes prices are included and that trademark and social-handle checks are NOT automated (links only), which is an important scope limitation an agent should know.

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?

Two tight sentences: a front-loaded framing question followed by the concrete coverage list. Every clause earns its place, with no redundant restatement of the name or title.

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 no output schema, the description does the work of sketching the return (domain results with prices, availability signals, and outbound links). Combined with annotations that fully cover safety, this is close to complete, only thin on how results are structured.

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% — both `name` and `tlds` (with default and maxItems) are documented in the schema itself. The description adds nothing parameter-specific beyond the already-covered notion of checking across TLDs, so 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?

The description gives a specific verb (checks) and enumerates the exact resources covered — domains across TLDs with prices, GitHub, npm, PyPI, crates.io — plus non-automated trademark/social lookups. This clearly distinguishes it from the narrower check_availability sibling, though it never names that sibling explicitly.

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 opening question ('Is a project name usable everywhere it'll be needed?') implies the use case — a broad pre-launch naming check — but there is no explicit when-to-use vs. check_availability, appraise_domain, or suggest_names guidance and no stated exclusions.

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