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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description's 'never write, send email or submit an enquiry' restates that read-only profile and it adds no auth, permission, rate-limit or failure-mode detail; the remaining text is operator-level legal context rather than tool behavior.

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?

The behavioral purpose is correctly front-loaded in the first clause, but roughly two-thirds of the text is regulatory/compliance boilerplate about the operator, referrer fees and Mainland visitors, which is only marginally relevant to selecting and invoking this lookup tool.

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 simple read-only lookup with no output schema, the definition covers the lookup key, the returned content ('published facts and links') and the safety profile (reinforced by annotations). Only the locale parameter and error/lookup-miss behavior remain unaddressed.

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 0%, so the description must carry parameter meaning. It clarifies that 'insurer' must be an exact catalog slug, which helps, but the 'locale' parameter (enum with a default) is never mentioned in the description and only self-documents via its enum values.

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 and resource ('look up one insurer by its exact catalog slug') plus what it returns ('public sourced facts'), which separates it from siblings like compare_products and get_product by implication. It never names a sibling explicitly, so it stops short of full differentiation.

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?

The phrase 'exact catalog slug' implies the caller must already have a precise identifier, and the disclaimers constrain how results may be framed, but there is no explicit when-to-use/when-not or routing to alternatives such as search_guides or compare_products.

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