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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new context — that results are denominated in USD and that it draws on 'Public data', implying no auth or user scoping — but says nothing about coverage gaps, caching, or behavior for unsupported country codes.

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: the first front-loads what is returned and in what units, the second supplies usage triggers. No filler, no repetition of the title.

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 parameter, no output schema, and annotations covering safety, the main burden is describing the return shape — and the description does enumerate the percentile cutoffs. A minor gap is what happens for countries without data, though the sibling list_supported_countries partly covers discovery.

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%, with the ISO 3166-1 alpha-2 format and the 'WORLD' sentinel fully documented in the schema itself. The description only adds that the country selects which national distribution is returned, which is close to restating the schema — 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 and resource ('Return the household net worth thresholds') and enumerates exactly which cutoffs come back (median, top 25%, 10%, 5%, 1%) for a given country. It implicitly separates itself from siblings like net_worth_percentile by taking a country rather than a net worth value, but never names an alternative explicitly.

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?

Gives a concrete trigger example ('what net worth is top 1% in the UK') and a second use case (building a wealth-distribution table), which is clear context for when to call it. It stops short of exclusions or naming which sibling to use when the question is the inverse (net worth → percentile).

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