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

The description adds substantial behavioral detail beyond annotations: it reads from the service's own crawl, answers in under a second, never visits the site during the call, and charges 0.5 credits only when an email or phone is found. These details clarify latency, data source, side effects, and billing conditions.

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 front-loaded with the core purpose and then adds only high-value operational details: crawl source, speed, shared-site limitation, and credit charge. Every sentence contributes useful information without 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?

For a single-parameter read operation with an output schema, the description covers the important call-context details an agent needs: what is returned, where the data comes from, expected speed, limitations, and cost. Nothing essential 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?

There is only one parameter, and schema description coverage is 100%, with the schema giving the URL/domain format and an example. The description does not add further parameter semantics beyond the schema, so the baseline of 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?

The description states a specific verb and resource: find emails, phones, and social profiles published on a company website. It is clearly distinguishable from person-level tools like persons_find_email and persons_find_phone by emphasizing contacts published on a company website.

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 gives a clear usage context and an explicit exclusion: websites shared by many businesses, such as site builders or booking platforms, have no contacts. It does not explicitly name sibling alternatives for person-level lookups, so it falls short of full when-to-use-vs-alternatives guidance.

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