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

Annotations are empty, so the description carries the full burden. It discloses the return fields and that data is 'normalized RDAP allocation' (implying read-only external lookup), but says nothing about rate limits, data freshness, error behavior, or how the lookup is scoped. Adequate for a read utility but leaves meaningful behavioral context unstated.

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 resource and enumerates returned fields. Efficient with no filler, though slightly congested by the parenthetical field list.

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?

The tool is simple (2 params, no output schema, no annotations), and the description covers the core purpose and return shape. However, without an output schema it should at least note result format, and it doesn't address when to prefer this over the sibling lookup tools.

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%, and the schema already documents both parameters including formats and prefix ranges. The description adds only that CIDR blocks are valid, which the schema's 'prefix' field already implies. No additional parameter semantics beyond the schema baseline.

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 (normalized RDAP allocation data for an IP/CIDR), and enumerates the returned fields. This distinguishes it from sibling asn-lookup and domain-lookup by making the target resource (IP allocation) clear.

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?

No when-to-use guidance is given. It does not clarify the choice between this and asn-lookup for IP-related queries, nor mention that CIDR blocks are acceptable inputs. The agent must infer the trigger from the name alone.

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