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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuine behavioral context beyond that: extraction is limited to 'public' content, affiliate disclosures and embedded-media text are excluded, and only dated/canonical URLs are accepted.

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, no filler. The core action and scope lead, and the input requirement plus exclusions follow. Every sentence 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?

Return values need not be described because an output schema exists, and annotations cover the safety profile. The description covers intent, input source, and content exclusions; only edge cases (e.g., non-dated or non-article URLs) are left to inference.

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 0% and the schema only types 'url' as a bare string. The description compensates by specifying that it must be a 'canonical dated article URL' sourced from a headline/article link, which disambiguates it from section, author, or homepage URLs accepted by sibling tools. It does not give a format example, so not a 5.

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 precise verb+resource: 'Extract public 9to5Google article metadata and readable body paragraphs.' The qualifier 'from one canonical dated article URL' scopes it against the sibling ninetofivegoogle_headlines/news/sections tools, so an agent can tell this is the single-article deep-fetch tool.

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?

Tells the agent where the input should come from ('Provide the URL from a headline or article link'), which implicitly routes from the headlines listing. It does not name alternative tools or state when NOT to use it, so it falls short of fully explicit routing guidance.

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