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 response shape (bio, social links, article list) but says nothing about pagination behavior beyond 'page selects the archive page', freshness, or limits. Adds modest value over structured fields.

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 tight sentences with no filler; the core action and returned content are front-loaded, and the sibling routing sentence follows. 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?

With an output schema present, the description needn't explain return values, and it correctly covers purpose, accepted identifiers, and the alternative tool. Only minor gaps remain around archive pagination and edge behaviors.

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%, so all three parameters (slug, url, page) are already fully documented, including the fact that page overrides a page number in url. The description restates the slug/url/page roles without adding syntax or format detail. Baseline 3 is appropriate.

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+resource ('Fetch a Live Science author's profile, biography, social links, and one page of recent articles') that enumerates the returned content and names the sibling it is not ('Use livescience_article for one story'). An agent can distinguish it from livescience_article/headlines/news 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 away from the sibling for the single-story case ('Use livescience_article for one story') and clarifies the one-page scope of the archive. It gives clear context but does not cover other likely alternatives or prerequisites.

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