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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-web nature are covered structurally. The description adds useful provenance context (a public Google News sitemap, implying recency-scoped results), but says nothing about result count, pagination, or update cadence.

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 the action, source, and payoff stated in order, 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?

With an output schema present, the description need not explain return values, and annotations cover the safety profile and open-world behavior. The one-sentence description adequately conveys source and content, though pagination or freshness-window details would make it fully complete.

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?

The tool takes zero parameters, so per the rubric the baseline is 4. The description correctly adds no parameter information because there is none to add.

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 verb and resource ('Fetch current GhanaWeb story metadata') and specifies the provenance (public Google News sitemap) plus the returned content ('fresh headlines and canonical article URLs'). It is clear on its own, but it does not distinguish itself from close siblings like ghanaweb_headlines or ghanaweb_article, so it stops short of a 5.

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?

'use this for fresh headlines and canonical article URLs' gives a clear usage context for a zero-parameter tool. There is no when-not guidance and no alternative sibling is named, which is acceptable given the tool takes no arguments, but it keeps the score below 5.

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