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

No annotations are provided, so the description carries the full burden. It does disclose the safety profile ('Read-only') and the upstream source (RIPEstat), which is useful, but says nothing about rate limits, cache freshness, pagination, or failure modes for a network lookup that can return many prefixes.

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?

A single front-loaded sentence that names the action, the resource, the data source, and the safety profile with no filler. The em-dash appositive is mildly redundant with the opening clause but still earns its place by defining scope.

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 one-parameter read-only lookup with no output schema, the description covers purpose, source, and read-only status adequately, and gestures at the return content ('with the network holder'). It could say more about the shape or volume of results, but nothing essential to calling it correctly is missing.

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 the schema already documents the single parameter with format examples ('13335 or AS13335'). The description adds no syntax, accepted-format, or interpretation detail beyond that, so the 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 ('List the IP prefixes an autonomous system announces') and even clarifies the notion with 'the routed footprint of an ASN', which separates it in spirit from siblings like asn_geoip or asn_relations. It never names an alternative explicitly, so it falls just short of full sibling 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?

There is no statement of when to use this tool, when not to, or which sibling to prefer (asn_geoip, asn_relations, rpki_validation all operate on ASNs). The usage is only inferable from the phrase 'routed footprint', which is descriptive rather than prescriptive.

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