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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds genuinely new context — content is in Japanese, every fact carries its source page URL, and nothing beyond the published pages is returned. It stops short of describing result shape or volume, but the added context is real.

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?

Three short sentences, each earning its place: what it returns, what accompanies each fact, and the read-only/source-bound guarantee. Front-loaded with 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?

With a single required enum parameter, full schema coverage, and no output schema, the description covers enough: content domain, language, return format (facts plus source URL), and fidelity limits. Minor gap is what 'all' yields and roughly how much content comes back.

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 enum values are self-describing, so the schema does the work. The description's topic list paraphrases the enum without adding format, scoping, or conflict-resolution detail (e.g., what 'all' returns).

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?

Names a specific verb and resource ('Returns the facts published on this website') and enumerates the fact categories, which line up with the topic enum. It is clearly distinct from check_ai_bot_access by subject matter, though it never explicitly contrasts with that sibling.

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?

Usage is only implied: it is the tool for published site facts. There is no statement of when to pick it over check_ai_bot_access, no note on whether topic='all' is the default approach, and no exclusions (e.g., that it will not answer questions about dynamic data).

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