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

Annotations cover the safety profile (readOnly, openWorld, idempotent), and the description adds useful context beyond them: that the call is free, the provenance domain (bankrolled.com), and an included cite line. It stops short of noting rate limits or freshness guarantees.

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?

Front-loaded with cost and purpose, then scope, then parameters, with no filler. Densely packed but each clause (supported countries, default topic, example) 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 no output schema, the description usefully enumerates the return fields (name, coverage headline, official source, as_of, source_url, cite line), which is exactly what an agent needs. Only minor gaps around error/unsupported-country behavior remain.

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 both parameters already carry enums, defaults, and an example, so the description largely restates structured data. It adds only marginal framing and no syntax beyond what the schema shows.

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 (look up) and resource (deposit-insurance scheme), then enumerates the returned fields, making the tool's scope unambiguous. It is clearly distinct from siblings health_check, money_fact, and pricing_list.

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?

It names the supported countries (US, UK, CA, AU, NZ) and the default topic, which constrains when the tool applies, but never states when to prefer it over a sibling or what to do for an unsupported country. Usage is implied rather than guided.

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