Find professional email addresses by providing first name, last name, and company domain; optionally include company name. Costs 2 credits.
Find professional email addresses. Cost: 2 credits.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Company domain. | |
| company | No | Company name (optional). | |
| last_name | Yes | Last name. | |
| first_name | Yes | First name. |
Changes observed during successful MCP inspections.
v0.3.1Input schema / properties / companyAdded value: +{
+ "description": "Company name (optional).",
+ "type": "string"
+}Input schema / properties / domain / descriptionPrevious value: -"Company domain (e.g. stripe.com)"New value: +"Company domain."Input schema / properties / first_name / descriptionPrevious value: -"Person's first name"New value: +"First name."Input schema / properties / last_name / descriptionPrevious value: -"Person's last name"New value: +"Last name."v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It does add one genuinely useful behavioral fact: the cost of 2 credits. But it omits whether the lookup requires an exact first/last/domain match, what happens on a miss, and whether results are verified/deliverable — significant gaps for a lookup tool with no annotation coverage.
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?
Two short sentences, no waste, with the core purpose front-loaded and the cost constraint immediately following. Nothing is padded.
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?
There is no output schema and no annotations, so the description should explain what a call yields (matched emails, confidence, no-match behavior). It says nothing about return values or failure modes, leaving the agent under-informed for a paid lookup.
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 all four parameters are already documented in the schema. The description adds no syntactic or semantic detail about them (e.g., whether 'company' changes matching behavior), so baseline 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 gives a specific verb+resource: 'Find professional email addresses.' That is clear enough to act on. However, it offers no differentiation from the sibling 'email-verify', which superficially sounds related, so an agent cannot confidently choose between them from the description alone.
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 when-to-use guidance, no prerequisite or input expectations, and no mention of alternatives such as 'email-verify' or 'companies'. The agent must infer usage entirely from the name and schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.