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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the bar is lower. The description still adds real value by disclosing the sort order (newest first) and that each row carries the IANA list version the change occurred in — information an agent cannot get from the annotations or schema. It stops short of noting pagination behavior or row-cap semantics.

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 short sentences, front-loaded with the resource and scope. The trailing marketing claim and the 'Served by NicheDB' attribution line are filler but do not obscure the core statement.

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 only three optional parameters, no output schema and full schema coverage, the description covers what the tool returns well enough (change rows plus IANA version, newest first). Missing only minor operational details like maximum page size or whether results are paginated.

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%, including examples for limit, since and change, so the schema already does the heavy lifting. The description adds only the ordering context ('newest first'), which lightly reinforces the since/limit semantics but supplies no additional meaning about accepted values.

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 combination — top-level domains added to or removed from IANA's root — plus ordering (newest first) and an extra returned field (IANA list version). This clearly distinguishes it from lookups like nichedb_search_tlds or nichedb_get_tld, though it never names an alternative 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: an agent can infer this is for auditing TLD additions/removals over time. There is no explicit when-to-use/when-not guidance, no pointer to nichedb_get_tld or nichedb_search_tlds for point lookups, and the 'Nobody else publishes this diff' sentence is promotional rather than directive.

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