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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read, open-web profile is covered. The description adds that cards include URLs, update times, and images, which is useful output context, but does not mention pagination limits or rate behavior beyond what the schema/page param implies.

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, fully front-loaded: the fetch action and its scope come first, then the routing alternatives. 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?

Given an output schema exists, the description need not detail return values, and annotations cover the safety profile. It correctly covers what the tool returns, when to use it, and what siblings to use instead – complete for an agent to select and call it correctly.

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% – the section param enumerates documented values and page documents the 100-items-per-page behavior. The description adds no parameter-level detail beyond what the schema already provides, so the 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?

Specific verb (Fetch) plus resource (recent article cards from one top-level Reuters section) and enumerates the returned fields (URLs, update times, images). This clearly distinguishes it from sibling tools like reuters_sections (section discovery) and reuters_articles (article content).

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 names three alternatives and the conditions that route to each: reuters_sections to discover sections, reuters_articles for content, reuters_news for the general feed. The agent knows exactly when not to use this tool.

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