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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds that articles are 'public' (implying no auth needed) and that it returns metadata and body paragraphs, which is useful behavioral content beyond what annotations convey.

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, zero waste, with the core fetch purpose front-loaded ahead of the discovery hint. 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?

An output schema exists so return values need not be explained in depth, and annotations cover the safety profile. The description supplies the discovery dependency and content scope, leaving only minor gaps like edge-case behavior for a simple one-parameter fetch.

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 the single url parameter is already documented as the 'Canonical NZ Herald article URL'. The description reinforces where the URL comes from (headlines discovery) but adds no format or syntax detail beyond the schema, so 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), resource (NZ Herald article), and scope (one, public), plus what is returned (metadata and body paragraphs). It also names the sibling (nzherald_headlines) used for discovery, letting an agent distinguish it from the headline/list tools without opening schemas.

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 to nzherald_headlines to discover article links, which establishes the intended workflow and dependency. It gives clear context but does not state exclusions (e.g., paywalled or non-article URLs), so it stops short of a 5.

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