List supported TLDs

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds pagination and page-scoped metadata fetching, but omits the non-obvious default that TLDs without registrars are filtered out by default.

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?

A single, front-loaded sentence with no filler; the primary purpose leads and the qualifiers follow. Compact, though the capability enumeration is somewhat dense.

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 6 parameters, no output schema and only half the parameters described, the description should at least explain the default filtering behavior and the paged return shape. It covers the headline features but leaves the agent guessing about omitted defaults.

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 coverage is 50%: query, punycode and includeMetadata are already documented in the schema, and the description merely restates them. The undocumented limit, offset and omitWithoutRegistrars get no compensating explanation, so nothing meaningful is added 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?

Names a specific verb and resource ("List extensions supported by TLD-List") and enumerates the capabilities (substring search, pagination, punycode, metadata). An agent can tell it is the bulk-listing tool rather than a variant/registrar lookup, though it never names a 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?

Usage is only implied from the capability list; there is no statement of when to prefer this over search_tld_variants or compare_tlds, and no prerequisites or exclusions. Adequate for retrieval, but the agent must infer routing.

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