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 and open-web nature are covered. The description adds only that results are 'current' and scoped to a 'public section'; it says nothing about pagination, result volume, or rate limits, so it adds modest context beyond annotations.

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?

A single front-loaded sentence with two clauses, one defining purpose and one defining the parameter's source. Every clause earns its place with no filler.

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 one-parameter, read-only tool with an output schema, the description covers purpose and the source of valid input values, which is sufficient for correct invocation. The remaining gap is parameter format, which the cited source tool likely resolves.

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 0%, so the description carries the burden for the single 'section' parameter. It meaningfully compensates by specifying that valid values must come from nzherald_sections, which is the key semantic an agent needs, though it omits the expected format (slug vs. display name).

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 gives a specific verb+resource ('Current NZ Herald headlines') and scopes it to 'one public section', which distinguishes it from the sibling nzherald_news broadly. It does not explicitly contrast with nzherald_news or nzherald_article, so it stops short of full sibling differentiation.

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?

It states a concrete prerequisite: the section value 'must come from nzherald_sections', which routes the agent to the correct tool to obtain valid input. There is no explicit when-not guidance or comparison against nzherald_news, but the dependency instruction is clear and actionable.

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