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

Annotations already cover the read-only, closed-world profile, but the description adds real behavioral context: concrete magnitude examples (RU 510 / IN 80 / IR 50), the ~42-country tag coverage, and the interpretive caveat that low depth means under-measurement rather than safety. It does not discuss caching, freshness, or response shape beyond the sample values.

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 the core definition before the caveats, and every clause carries information. It is dense and dash-slash heavy in a single run-on paragraph, which costs some readability.

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, one optional parameter, and a read-only annotation set, the description supplies what an agent needs: what the number means, what it does not mean, sample values, and single-country vs full-set behavior. Nothing material is left unclear.

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 the baseline is 3, but the description adds meaning the schema omits: passing country=XX scopes to one country, implying omitted means the full tagged set, and it clarifies the code semantics with ISO examples.

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 precise verb and resource: per-country count of distinct ISP networks (ASNs) Voidly has evidence from. The framing ('proxy for independent vantage points', 'bounds what the >=3-network confirmed-block gate can confirm') makes it clearly distinguishable from siblings like get_data_confidence or get_probe_stats.

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 clear context for when the number matters (gauging how well-backed a country's confirmed-block data is) and an explicit caution against misuse ('NOT a censorship score; absent/shallow is under-measured, not free'). However, it never names an alternative tool or states an explicit when-not-to-use condition.

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