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 safety profile needs no restatement. The description usefully adds ordering (newest first) and that each row carries the IANA list version, but says nothing about volume, pagination, or how far back the history goes.

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 sentences, no filler, with the resource and ordering front-loaded and the differentiator placed last. Every clause earns its place.

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 should describe the record shape; it names ordering and the version field but not the other fields. It also omits the "returned" change type that the schema's change param allows, so a reader could mistakenly conclude only added/removed events exist.

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 100% and each of the three params (limit, since, change) carries its own description with examples, so the schema does the heavy lifting. The description adds no syntax or filtering nuances beyond it, leaving this at the baseline 3.

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 concrete resource and scope: TLDs added to or removed from IANA's root, plus ordering (newest first) and included field (IANA list version). An agent can distinguish this from get_tld/search_tlds by the fact that it returns change events rather than lookups, though it never names those siblings 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?

"Nobody else publishes this diff" hints at a unique use case, but there is no explicit when-to-use or when-to-prefer-get_tld/search_tlds/upcoming guidance. Usage is implied by the diff framing rather than stated.

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