hunter_domain_info

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds only 'from Hunter.io', which hints at a third-party external call already implied by openWorldHint; it says nothing about API-key requirements, quotas/credits, or what the response contains.

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?

A single short sentence is front-loaded and wastes no words, but brevity here is under-specification rather than economy — the one sentence could easily absorb a clause about what is returned or which sibling to prefer.

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 no output schema, two undocumented parameters (one of them an auth credential), and no return-value detail, the definition leaves an agent unable to predict the response shape or reliably supply the API key. It is too thin for a tool that hits a credentialed third-party service.

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%, so the description must carry the load, but it only implies the 'domain' parameter exists and says nothing about 'api_key' — including whether it is required, whether it can come from an environment variable, or what format the domain should take (bare hostname vs URL).

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?

States a clear verb and resource (get email information for a domain) but 'email information' is vague — it does not say whether this returns a company profile, an email pattern, contact counts, or a full contact list. It also does not distinguish itself from siblings hunter_find_email and hunter_verify_email, which an agent could easily confuse with it.

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?

There is no guidance on when to use this versus hunter_find_email (to find a specific person's address) or hunter_verify_email (to validate an address). No prerequisites or exclusions are stated, leaving the agent to infer that this is a domain-level lookup.

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