discover_companies

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

No annotations are provided, so the description carries the full burden. It discloses that this is a read-only discovery operation via Hunter.io, but does not mention API rate limits, authentication requirements, or what happens when fetch_emails is enabled (cost/rate implications). The 'Optionally fetch contact emails' note adds some transparency about behavior not obvious from schema.

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 a compact two-sentence statement that conveys the core purpose and the key optional behavior. It's front-loaded with the primary action and appends the supplemental capability. Minimal waste, though it could add brief guidance without bloat.

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 an 8-parameter discovery tool with no output schema and no annotations, the description is somewhat thin. It doesn't mention what the returned company objects look like, how results are ordered, or the implications of the fetch_emails flag (e.g., slower, rate-limited). The schema covers parameter semantics but the description doesn't help the agent set expectations for return data or API reliability.

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 schema fully documents all 8 parameters including ranges and defaults. The description adds context that fetch_emails triggers additional behavior (email fetching), which is useful. However, it doesn't add meaning beyond the schema's parameter descriptions such as how query interacts with filters or typical usage patterns.

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 ('discover') with a clear resource ('companies') and mentions the Hunter.io backend plus the optional email fetching capability. It clearly distinguishes from sibling tools like enrich_lead or verify_emails by focusing on company discovery rather than lead/email operations.

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 usage for company discovery and optionally fetching emails, but provides no explicit guidance on when to choose this over alternatives such as search_leads or enrich_lead. The email-fetch distinction is noted but not framed in terms of selection criteria.

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