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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint and destructiveHint=false, so the safety profile is fully covered elsewhere. The description adds little beyond that — it says what fields come back but not result ordering, freshness, rate limits, or that results come from the GNews provider. A 3 reflects modest added context with no contradiction.

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?

Three short sentences, front-loaded with the core action, then outputs, then filters. No filler, though the middle sentence listing return fields is largely wasted given an output schema exists.

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 explain return values, and the annotations carry the safety profile. What remains adequate: it covers scope and filters, though it omits result ordering, freshness, and any note on how to broaden/narrow a search across the 1-100 max range.

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%, with defaults and ranges already documented for max, lang, country, and query, so baseline is 3. The description's mention of language and country filters merely restates the schema and adds no new semantics such as filter interaction or whether country implies lang.

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 uses a specific verb+resource ("Search global news articles by keyword") and gives example queries that make the scope concrete. It does not, however, distinguish itself from the closest sibling, top_headlines, which an agent could reasonably consider for the same underlying need.

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?

Usage is only implied by the keyword-search framing; there is no explicit statement of when to prefer this over top_headlines or search_within, and no exclusions or prerequisites beyond what the schema shows. An agent can infer the intent but is left to guess at alternatives.

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