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 genuinely useful behavior context beyond that: it returns both metadata and body paragraphs, it covers public content only, and it requires a canonical URL. It does not mention auth or rate-limit behavior, but with annotations carrying the safety profile this is solid.

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 with zero filler. The primary purpose and input are front-loaded, and the routing guidance follows immediately after in the same breath.

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?

For a single-parameter read tool with an output schema and readOnly/openWorld annotations, the description covers everything an agent needs: what is fetched, what the input must be, and which sibling to use for adjacent tasks. Return-format detail is correctly deferred to the output schema.

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% and the single parameter already documents itself as a 'Canonical ABC News Australia article URL'. The description's mention of a canonical `url` restates that rather than adding format or example detail, so the 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?

States a specific verb ('Fetch') plus resource ('ABC News Australia article metadata and body paragraphs') and the exact input it draws from ('canonical `url`'). It also names the sibling it is not (abcnews_article for the U.S. site), so an agent can distinguish it from the surrounding news-article tools without opening a schema.

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?

Explicitly routes the agent: use abcau_headlines or abcau_news to find story links, abcau_author for a byline profile, and abcnews_article for the U.S. site. This is a when-to-use and when-to-use-something-else statement with named alternatives, leaving little to inference.

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