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

With no annotations, the description carries the behavioral transparency burden. It does well by distinguishing probe-verified signals from unverified apparent actions, explaining verification tiers and discovery sources, and explicitly describing empty-result behavior with 'never a nearest guess.' It does not mention auth, rate limits, or read-only status, but the behavioral semantics of the results are unusually well disclosed.

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 compact and front-loaded with the core purpose. Every sentence adds value: the first declares what the tool does, the second enumerates return contents, and the third clarifies empty-result behavior. There is no filler or redundancy.

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 description is reasonably complete for a search tool: it states the output fields, explains how results are verified or unverified, and specifies the empty result behavior. It does not cover interpretation of verification tiers or explicit guidance on composing filter parameters, but those are partly addressed by the schema. Without an output schema, the description does enough to set correct expectations.

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 high (~78-89%), and most parameters already have detailed descriptions in the schema. The tool description itself does not add parameter-level meaning beyond the schema. Per the baseline for high coverage, a 3 is appropriate.

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 uses a specific verb-resource pair: 'Find websites where an agent can accomplish a task.' It clearly describes what the tool returns, including agent-readiness signals, verification tier, and discovery method. It does not explicitly name or contrast the sibling get_site_report, so differentiation is implied rather than stated.

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 implies when to use the tool: when you want to discover sites where an agent can accomplish a task. It does not mention alternatives, when not to use it, or how it relates to get_site_report. The usage context is clear but no exclusions or alternative routing are provided.

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