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

Annotations already communicate read-only, open-world, and idempotent behavior. The description adds no extra context such as response format, data source, or any limitations. Since there is no output schema, the description should disclose what a lookup returns (e.g., geolocation fields), but it does not.

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?

The description is very concise at only four words, which is structurally simple and front-loaded. However, it sacrifices necessary information for brevity, making it less effective than a slightly longer description could be.

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 a single parameter and no output schema, the description carries the full burden of explaining what the tool does. It only states 'HackerTarget geoip lookup,' which is insufficient for an agent to know how to set the target or what to expect in response. Given the tool's simplicity, a more complete description is expected.

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 schema defines a single required string 'target' with 0% description coverage. The phrase 'geoip lookup' implies the target is an IP address or hostname, but this is not explicitly stated. The description fails to adequately compensate for the lack of parameter documentation.

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 'HackerTarget geoip lookup' clearly identifies the tool as a GeoIP lookup service powered by HackerTarget. It distinguishes itself from siblings like dns_lookup and whois by focusing on geographic IP data. However, it lacks details on input format and output, preventing a top score.

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?

The description offers no guidance on when to use this tool versus alternatives. It does not explain whether it is for IP addresses, domains, or how it complements other recon tools. Given the large sibling set, explicit context is essential but missing.

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