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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety profile is covered. The description adds useful context beyond that: the content is public (implying no auth) and the return payload comprises metadata plus body paragraphs. It does not discuss failure modes for malformed/non-canonical URLs, keeping it just under a 5.

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. Capability is front-loaded, with the sibling-routing guidance following. Every clause earns its place.

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 read-only fetch tool with an output schema already describing return values, this covers everything an agent needs: what it returns, where the input comes from, and how to get URLs from sibling tools.

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% and the schema already documents the single url parameter as the canonical PC Gamer article URL. The description's phrase 'from a canonical URL' reinforces but does not meaningfully extend the schema, 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?

States a specific verb (Fetch) and resource (PC Gamer article metadata and body paragraphs) with scope (from a canonical URL). An agent can distinguish it from pcgamer_headlines, pcgamer_news, and pcgamer_author 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 routes the agent: use pcgamer_headlines or pcgamer_news to discover stories, and pcgamer_author for byline details. This tells the agent when not to use this tool and which siblings to use instead.

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