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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only the word 'public' and a hint at payload shape, both of which are largely redundant given the output schema exists; no auth, rate-limit, or failure behavior is disclosed.

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?

One compact sentence with no filler and the key noun (the resource) front-loaded. It is efficient, though as a bare noun phrase it conveys less than a slightly longer verb-led sentence would.

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?

The output schema means return values need not be explained, and the tool is a simple one-parameter fetch. However, with zero parameter documentation and no guidance on sourcing the URL from the sibling listing tools, the definition leaves the agent to guess at invocation details.

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 0% for the single required 'url' parameter, and the description says nothing about it. It does not clarify whether a full URL, a path, or a slug is expected, nor where a valid value can be obtained.

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 names a specific resource ('one public RNZ article') and scopes it to a single item, distinguishing it implicitly from the list-oriented siblings rnz_news and rnz_headlines. It lacks a verb ('retrieve/fetch'), but the resource and cardinality are unambiguous.

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?

There is no when-to-use guidance and no mention of where the required URL comes from (e.g., rnz_headlines/rnz_news results). Nothing tells the agent this is the follow-up call after a listing tool, nor when rnz_author or rnz_sections would be preferable.

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