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

Goes well beyond the readOnlyHint/openWorldHint annotations: explains that links redirect to the publisher, that article text is NOT returned, the edition/language scope, and the billing model ($0.002 per successful call via x402, failed calls free). These are exactly the operational facts an agent needs before invoking a paid, open-world search.

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?

Front-loads capability and return fields before the sibling routing and pricing, so the important content is read first. The sibling/pricing tail is dense but each clause carries operational value; no filler sentences.

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 needn't detail return structure, yet it still summarizes returned fields and the key limitation (no article text). Combined with cost disclosure and edition scope, nothing an agent needs to call it correctly is missing.

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%, documenting both q (1-200 chars) and limit (1-30, default 10), so the baseline applies. The description only adds the implicit ordering ('newest matching stories') and no syntax or query-format guidance beyond the schema.

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?

Names a specific verb and resource ('Google News search') and immediately states the underlying mechanism (public Google News RSS feed, no key, English/US edition) plus the exact returned fields: headline, publisher, publish time and link. This is fully distinguishable from news siblings such as search_reuters_articles or search_gdelt_news.

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 two named alternatives with their triggering conditions ('search_google_ads when you need...', 'search_google_search when you need...'). It does not say when NOT to use this tool versus the large set of other news-source siblings, so routing guidance is clear but incomplete.

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