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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), but the description adds genuinely useful context beyond them: the 7-day observation window, hourly refresh cadence, partner-tier requirement, and per-call price. Return shape is sketched but no detail on freshness lag, payload size, or throttling.

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 tight sentences, front-loaded with the resource and scope, then tier/pricing, then return shape. Every sentence carries distinct information an agent needs before spending a call.

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 parameters and no output schema, the description must carry the return-value burden, and it does name the top-level fields. The nesting of networks/bots/fingerprints is only gestured at, so an agent knows the shape but not the element structure.

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?

The tool takes zero parameters, so per the rubric the baseline is 4. The description instead describes the response contents (generated_at, networks, bots, fingerprints), which is appropriate for a parameterless feed.

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?

The description defines a very specific dataset: ASN-level networks, named crawlers, JA4 TLS fingerprints and firewall rules observed over the last 7 days, refreshed hourly. It is clearly a data-retrieval feed and could not be confused with domain_whois or site_status, though it never explicitly contrasts itself with any sibling by name.

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 routes the agent well by naming the free alternative (https://dns.pizza/bots) and stating exactly what that tier lacks ('same shape without fingerprints'), which implies when this paid partner tier is required. There is no explicit when-not-to-use guidance, but the tier/cost tradeoff is spelled out.

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