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

The description adds substantial behavioral context beyond the readOnlyHint and openWorldHint annotations: data comes only from the company's own website, role emails are MX-checked, phones are E.164, personal emails and names are omitted for GDPR, robots.txt is respected, and pricing/payment mechanics are 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 fairly dense but front-loads pricing, then purpose, then usage. Most sentences carry useful information, though the payment details are prominent enough to slightly dilute the core tool-purpose framing.

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?

Given an output schema, full schema coverage, and annotations, the description provides enough context for correct invocation: it covers the data scope, exclusions, validation behavior, payment requirements, and intended use case.

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%, so the two parameters are already documented in the schema. The description implies domain and country semantics through 'company domain' and 'main phone', but does not add meaningfully more parameter guidance than the schema provides.

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 clearly states a specific resource and scope: public business contact details from the company's own website, including role emails, main phone, address, company/VAT IDs, and official social profiles. It does not explicitly name or differentiate from the closely related sibling site_contacts, which keeps it from a 5.

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 an explicit use case: 'Use company-contacts for public role emails and main phone of a company domain (no personal data).' It does not say when not to use it or name alternative siblings, so the guidance is clear but not complete.

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