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

Annotations already declare readOnly, idempotent, non-destructive, and open-world, so the description correctly focuses on what those hints don't cover: the crawl scope ('homepage and a few contact/about pages, nothing behind a login'), the one-at-a-time constraint, and the auth requirement ('Needs a free SnoopScan key'). No rate limits or failure modes are mentioned, keeping it short of a 5.

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?

Three short, purposeful paragraphs with the returned-fields detail grouped together and the alternative-tool pointer at the end. The opening line is somewhat atmospheric rather than operational, and the auth-key requirement ('Needs a free SnoopScan key') is buried last where an agent would rather see it before committing to a call.

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 an output schema present, return values needn't be explained, and annotations cover the safety profile; the description fills the remaining gaps around crawl scope, single-company operation, auth needs, and the sibling alternative. The one real omission is the undocumented `contacts` parameter, which is more a parameter-semantics issue than a completeness failure.

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 0% for two parameters. The description implies the `url` input ('Give it a company domain') but never states the format, and it says nothing at all about the `contacts` boolean, which materially changes the response. With coverage this low the description must compensate and it only does so for half the parameters.

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 resource and action – profiling a company's own website – and enumerates the returned fields (name, phone, address, LinkedIn, headcount, industry, founded year, emails, socials, contact form). It explicitly distinguishes itself from the sibling `findLeads` by contrasting 'profiles one company at a time' with 'find businesses by trade and place'.

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 names the alternative tool and the condition that selects it ('To find businesses by trade and place, use findLeads'), and implies the when-not boundary with 'nothing behind a login.' It does not address other plausible siblings like `domain`, `people`, or `scrape`, so the routing guidance is clear but not exhaustive.

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