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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds the 'public' qualifier (implying no auth needed) and states the return content is metadata plus body paragraphs. It does not mention rate limits, truncation, or pagination, but with annotations and an output schema in place this is adequate.

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, zero waste. The core capability is front-loaded in sentence one and the routing guidance follows immediately in sentence two.

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 single-parameter fetch tool with full schema coverage, an output schema, and annotations covering the safety profile, the description supplies everything an agent needs: what it returns, the required input, and how it differs from the discovery siblings.

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?

Only one parameter with 100% schema description coverage, so the schema already documents it. The description's 'canonical url' phrasing adds a mild constraint (must be a canonical article URL, not a search page) beyond the schema's 'Canonical Newsweek article URL', which is marginal.

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?

States a specific verb ('Fetch'), the exact resource ('public Newsweek article metadata and body paragraphs'), and the input required ('canonical url'). An agent can distinguish it from the sibling newsweek_headlines/newsweek_news/newsweek_author tools without opening any schema.

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 sibling alternatives and the condition each serves: headlines to find stories, news for the general feed, author for a byline profile. This routes the agent away from misusing this tool for discovery, leaving nothing to inference.

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